Yeshaiahu Fainman - US grants

9311062 Fainman The goal of this proposal is to conduct basic research towards development of the polarization sensitive optical elements for passive switching fabric interconnection networks and for packaging of manufacturable optoelectronic systems. We propose to employ the approach of computer generated hologram (CGH) design of diffractive optical elements that possess two different impulse responses for two orthogonal polarizations. To obtain the dual impulse response functionality we will use two surface relief microstructures in birefringent material assembled face to face. The fabrication of these elements will leverage from the advances in the microelectronics technology using E beam lithography, photolithography, ion beam etching, ion implantation, etc. The objectives of this proposal include modelling, design, fabrication and testing of multilevel phase polarization sensitive diffractive optical elements built of naturally birefringent materials as well as of artificially birefringent materials obtained with form birefringence. In addition to the optoelectronic systems applications, the proposed research advance the basic science and engineering in such areas as vector optical wave diffraction on quantized multi level phase birefringent boundaries and microstructures, and microfabrication of CGH using deposition and ion implantation techniques. ***

9415834 Fainman A hybrid optical/electronic system that uses holographic optical elements for the inspection of machined parts is proposed. With this approach, a holographic optical element corresponding to the part is generated using the database that exists in the computer- aided design system. The holographic optical element stores information on the geometry of the ideal designed part, which is later compared with the real, machined part. The comparison is done by an optical system interfaced with a microcomputer to obtain digital output. With this strategy, instead of measuring the absolute values of the shape, the PI measures only the deviations of the actual part surface from the designed part. Measuring deviations instead of absolute values may increase the measurement resolution and accuracy by orders of magnitude. The proposed research on the development of a CAI system will have a significant impact on manufacturing technologies because it will provide tools that will allow different subsystems in the manufacturing processes to be integrated in real time. The proposed studies will also advance the areas of optical signal processing and optical computing. For example, new approaches to encoding problems for computer holography will be introduced, and a new method based on the optical utilization of a priori knowledge will be developed for image processing, pattern recognition and machine vision. The Technology Reinvestment Project of ARPA has recently established a Manufacturing Engineering program at UCSD; thereby the proposed work will also have a unique impact on the education of students at the graduate and undergraduate levels in manufacturing engineering. They will gain extensive first-hand experience in the growing field of optics in general and in optical sensing and optical signal processing in particular. The students background will be further enhanced through special courses and seminars related to this subject. The PI expects that the unique background of the students (i.e., optical technology and manufacturing systems, including CAD, CAM, and robotics) will be an important factor in the introduction and efficient integration of advances in optical technology into different areas of U.S. manufacturing industry. ***

9422069 Jain For the past decade, the importance of visual computing has increased exponentially. Visual computing, which embraces processing, interpreting, modeling, assimilating, storing and synthesizing visual information, now plays a pivotal role in many fields. These include such subjects as: virtual reality, multimedia, robotics, computer-human interaction, scientific visualization and communication. This award is to purchase equipment for supporting a number of ongoing research projects that are committed to this important field. The goal of these projects is to improve visual information computing through innovative experimental research. The equipment which include two visualization systems, one real-time image processing subsystem, and a number of visual sensors will be dedicated to support four individual research projects each addressing a different aspect of visual computing, namely Visual Information Assimilation, Visual Interaction through Gesture Recognition, Modeling and Design of Optoelectronic Visual Information Processors, and Physics-based Visualization of Multipedal Walking Systems. ***

Proposal Number: ECS-9810102 Principal Investigator: Y. Fainman (University of California San Diego) Title: 3-D Quantitative imaging and Correlation by Spatially Incoherent Chromatic Interferometry Abstract The proposal is to study the use of newly developed diffractive optical components to perform 3-dimensional profiling optically and quickly for application in reconfigurable manufacturing system. The proposed research will have significant impact on the next generation manufacturing technologies as it will allow integration of on-line parts inspection in real time into manufacturing systems.

In this project, three researchers, and a team of graduate students, from
the University of California, San Diego (UCSD), shall undertake
theoretical and experimental investigations of data modulation schemes for
efficient information transmission in conjunction with CDMA encoded
ultrashort pulses in an optical fiber. Efficient modulation formats will
result in aggregate transmission rates exceeding one terabit/second, with
individual user rates on the order of 100-1000 megabit/second. The specific
objectives of this project include modeling of the CDMA, statistical
analysis of the transmitted waveforms, investigation of various CDMA codes
that support thousands of users with minimal interference, bit error rate
analysis of received signals for various modulation schemes, means to
provide QOS levels, modeling and characterization of the distortions
induced by the fiber channel, adaptive equalization techniques for reducing
fiber distortions, computer simulations of the modulation schemes, and
experimental evaluation of the modulation schemes, transmitter, optical
channel, and receiver. The goal of this proposal is to demonstrate a
prototype network with several users employing a modulation format which
when scaled up to the full number of users will carry over one terabit per
second of information.

The potential impact of the work will be in the proof that CDMA encoding of
ultrashort pulses is a realizable and desirable alternative to wavelength
division multiplexing (WDM).

0088060
Fainman

There is a growing demand for the miniaturization of chemical and biological sensors for environmental, medical and security applications. Of great interest for such applications are low-power, compact, and cost effective micro-systems that combine non-electrical sensing capabilities and electronic processing. The goal of the proposed work is to conduct basic research towards the development of high sensitivity chemical and/or biological sensors integrated on a monolithic Si substrate. This multi-disciplinary study will focus on fundamental understanding of nano-scale chemical, biological and near-field optical interactions, leading to the development of design and implementation methodologies for porous silicon (Psi)-based sensor micro-systems. The proposed micro-systems will use optical transducers based on microfabricated optical sources combined with optimized nanostructured resonant optical filtering devices and photodetectors, allowing label-free detection of analytes with significantly higher sensitivity than existing techniques (e.g. surface plasmon resonance or optical interferometry). This technique will be applicable to a variety of sensing problems in environmental monitoring, medical diagnostics, high-throughput screening, and pharmacogenomics applications. The PIs propose to study two complementary aspects of this emerging technology: (a) investigation of the correlation between the modification of the optical properties of PSi and the concentration of different species introduced in the pores, including nerve agents, solvents, or biological molecules; and (b) design, modeling, fabrication and testing of monolithically integrated near-field meso-optic structures built using micro- and nano-fabrication techniques.

The proposed research will not only have a significant impact on the development of on-chip monolitically integrated micro-sensor systems, but also result in the development of basic science and technology of near-field linear and nonlinear optical phenomena in nano-scale and meso-scale structures. The proposed studies will also advance basic science and engineering in such multidisciplinary areas as vector field optical wave interactions in near-field nonlinear dielectric nanostructures, quantum and nonlinear optical processes in nanostructured composite materials, and fabrication of such devices using deposition, photochemistry, and ion implantation techniques. The proposed project will also play a unique role in the education and development of human resources in science and engineering at the graduate and undergraduate levels.

9912476
Fainman

Given the enormous increase in communication capacity provided by high bandwidth optical fibers, new technologies will soon be necessary to provide ultra-high bandwidth switching and networking capabilities. The bandwidth available in optical fibers is currently exploited using wavelength and time division multiplexing techniques, both of which increasingly rely on the ability to generate, detect, switch, multiplex and demultiplex optical information-carrying waves using direct efficient nonlinear optical interactions. Growth in the capabilities and applications of these technologies using existing nonlinear optical materials and devices is limited by efficiency (due to the relatively small effective nonlinear coefficients and the short effective interaction lengths imposed by dephasing).

The goal of this proposal is to conduct basic research towards the development of efficient optical nonlinearities exploiting the near field interactions in artificial nanostructures. The proposed approach will focus on: (i) enhancement of optical nonlinearities by engineering nanostructures that exhibit local-field concentration, (ii) incorporation of the optical nonlinearity enhancement due to the very high field effects achievable with ultrashort laser pulses, and (iii) engineering broadband phase-matching nano- and micro-structures to meet the needs of optoelectronic and imaging systems (e.g., using the unique properties of photonic crystals to allow operation in broad angular and wavelength bands). The specific objectives of this proposal include rigorous modeling, design, fabrication and characterization of these novel nonlinear optical nanostructures. Special emphasis will also be given to our ultimate objective of using these enhanced optical nonlinearities to build functional meso-optic devices and components that will have a significant impact on optical communication networks (e.g. wavelength converters, space-to-time and time-to-space demultiplexers, switches, etc.) and imaging systems (e.g. time-gating for biomedical imaging), as well as on additional novel applications (e.g. higher order harmonic generation for high-resolution optical lithography).

The proposed research will not only have a significant impact on the development of all-optical nonlinear processors for optical communication networks and imaging systems, but also result in development of the basic technology for studying the near field nonlinear optical effects in meso-scale optical architectures. The proposed studies will also advance the basic science and engineering in such areas as vector optical wave diffraction in near-field nonlinear dielectric nanostructures, understanding of nonlinear optical processes in nanostructured materials, and fabrication of such devices using deposition and ion implantation techniques. The proposed project will also play a unique role in the education and development of human resources in science and engineering at the graduate and undergraduate levels, as under our prior NSF support (contributing to over 100 manuscripts in refereed journals and conference presentations, the completion of 6 Ph.D. and 5 M.Sc. degrees, NSF REU for 8 undergraduate students, and the current supervision of 10 Ph.D. students).
***

In this proposal, three researchers from the University of California, San Diego (UCSD), specializing in the fields of optics, communications, and computer networks, are collaborating on the Ultra-High-Capacity Optical Communications and Networking initiative. It is felt by many researchers that the most efficient and economical way to utilize optical transmission technology for large scale networking is to use wavelength division multiplexing (WDM) in a circuit switched mode, overlaid with packet switching implemented with electronics. While this may indeed be the case, it is important to investigate alternative approaches that have great potential. The UCSD team has been investigating novel techniques of information transmission via optical fiber, where code division multiple access (CDMA) using ultrashort laser pulses is employed. Compact, low cost fiber-based ultrashort pulse sources are currently being developed, making the technology suitable for future practical networks. When an ultrashort pulse is encoded for CDMA, the pulse spreads out in time and resembles a noise burst that is transmitted on the optical fiber. At the receiving node, a decoder is applied to the received signals from multiple users, which matches only the encoding of the desired transmitter. The matching signal component is transformed back to an ultrashort pulse form that can be detected over the remaining interference from other users with nonlinear optical techniques. A novel high resolution pulse synthesis and detection technique for ultrashort pulses developed at UCSD enable various data transmission formats to be considered, such as ultrafast packet transmission with on/off keying, pulse position modulation, and amplitude modulation. The CDMA scheme enables large scale, asynchronous, concurrent access to the transmission resources. With a suitable architecture, this can be exploited to simplify network control, and increase reliability and flexibility.

The objective of this proposal is to conduct basic research by investigating theoretically and verifying
experimentally data modulation schemes for efficient information transmission in conjunction with CDMA encoded ultrashort pulses in an optical fiber network. Efficient modulation formats will result in aggregate transmission rates exceeding 10's of terabits/second, with individual user rates on the order of 1-10 gigabits/second. The specific objectives of this proposal include modeling of the optical CDMA for ultrashort Gaussian pulses, complete statistical analysis of the transmitted waveforms, investigation of various optical CDMA codes that support thousands of users with minimal interference, bit error rate analysis of received optical signals for various modulation schemes, modeling and characterization of the distortions induced by the fiber channel, adaptive equalization techniques for reducing dispersion and other fiber distortions, computer simulations of the modulation schemes, and experimental evaluation of the communication system: transmitter, optical channel, and receiver. The various phases of the proposed project complement each other. Combined together, they provide for in-depth knowledge of the theoretical and experimental issues of communicating with CDMA encoded ultrashort pulses. These findings will be shared with the scientific community, enhancing not only the knowledge base of other researchers in the field, but also of the students conducting the research. We shall demonstrate a prototype optical network with several users employing the modulation format that will carry over 10 terabits per second of information, when scaled up to the full number of users.

The potential impact of the work will be in the proof that optical CDMA encoding of ultrashort pulses is a
realizable and desirable alternative to WDM. Currently, WDM is the preferred multiplexing method due to its
simplicity and low cost. While WDM does increase the transmitted bandwidth significantly, it still does not fully utilize the available optical bandwidth due to both the need for guard bands between channels and the under utilization of channels. In contrast, CDMA encoded ultrashort pulses share the entire bandwidth without the need for guard bands, leading to efficient utilization of transmission resources. Using CDMA can also provide a highly flexible and robust infrastructure, upon which packet switching can be overlaid. The CDMA format also provides a degree of security, as no data can be extracted without knowledge of the codes employed.

0304573
Fainman

Nanoscale science and technology are playing an increasingly important role in development of future technologies for information systems including computing, communications, display, lighting, high-resolution imaging, and sensing. Optical and photonic technologies are recognized as enablers in most of these applications. However, construction of engineered nanostructured optical materials, resonant nanostructures such as photonic crystals, and integrated nanophotonic active and passive devices and systems is one of the most challenging tasks. It is evident that further advances in nanophotonic technology will rely on our ability to develop (i) efficient design and modeling tools, (ii) advanced nanofabrication techniques, and (iii) visualization and imaging tools (for both structural and functional tests). These challenges need to be investigated in an integrated program enabling evaluation and comparison of the calculated predictions and the experimental verifications.

The objective of this proposal is to conduct basic research by investigating theoretically and verifying experimentally the complex amplitude of the near-field on the nanoscale and with femtosecond time resolution for various nanophotonic devices at operation wavelength. The proposed research will focus on (i) construction of a near-field optical microscope allowing measurement of the amplitude and phase of optical near-fields with femtosecond resolution; (ii) experimental investigation of the optical field and its localization in nanophotonic devices, and (iii) study of near-fields in optical nanostructures operating in a nonlinear regime. The proposed research will investigate near-field interactions in artificial nanostructured materials, which provide a variety of functionalities useful for optical systems integration. Furthermore, near-field optical devices facilitate miniaturization and simultaneously enhance multifunctionality, greatly increasing the functional complexity per unit volume of the photonic system. Since the optical properties of near-field materials are controlled by the geometry, there is flexibility in the choice of constituent materials, facilitating the implementation of a wide range of devices using compatible materials for ease of fabrication and integration.

The proposed research will significantly impact the development of advanced nanophotonic devices and systems utilizing nanoscale architectures. Thereby, the proposed research will not only bolster the area of near-field optical physics and engineering, but will also extend to aid in the development of nanoelectronics, nanomagnetics, nanomechanics, chemistry, and biology by providing a fundamental characterization technology. Research and training of graduate and undergraduate students in the new field of nanotechnology will have a significant impact on the society as it will revolutionize numerous technologies of critical importance for life science, advanced information sciences, and national security.

The proposed project will investigate a broad class of packet-based network architectures, protocols, and services where the core switch/route fabric has limited or no buffering capability. These networks - called mbuffered networks - have two distinguishing features. First, packet loss due to contention is treated as an erasure that can be corrected via coding techniques. Information is encoded into code words and each codeword is divided into fragments. The redundancy built into the codeword acts like a "virtual buffer" that mitigates contention and packet loss so that if several of the codeword fragments are erased as they pass through the network, there is still a high probability that the information within the codeword can be decoded correctly at the destination. Adaptive flow control can be implemented by adjusting the coding overhead (code rate) as well as the fragment generation rate. The second distinguishing feature is the robustness with respect to hardware and routing failures. In particular, different codeword fragments belonging to the same codeword can be sent using different routes within the network to increase resilience. Route diversity also provides unique security and authentication features.

The intellectual merit of the proposed project is the exploration of new architectural approaches that use little or no buffering in high-speed networks where buffers are becoming increasingly difficult to implement. Results of this project will impact research directions in optical systems technology, and increase the base of knowledge in communication systems theory. The project will provide unique training of both undergraduate and graduate students in a systems-oriented multi-disciplinary effort.

P.I. Papen, George Proposal #: 0428900

Project Summary
Nanoparticles, or colloids in aquatic environments, have sizes ranging from 1 to 1000 nm and are at the boundary between soluble chemical species and sinking particles. They are the most abundant particles in the ocean and other aquatic environments and account for a significant portion of "dissolved" organic carbon. In situ characterization of the physical and biochemical properties is crucial for a wide range of fundamental applications including: 1) ocean biogeochemistry 2) ocean optics and 3) aquatic biological hazards.

While the characteristics of nanoparticles are important for a variety of applications, their complex heterogeneous nature and small size makes the in situ determination of their physical and chemical characteristics extremely challenging. To date, most characterization techniques are laboratory-based and are thus limited. This project will develop in situ sensor networks for aquatic nanoparticle characterization that can address a broader range of applications and test them in an ocean environment. The research program consists of the development of microfluidic-based techniques that can preprocess and help analyze heterogeneous assemblies of aquatic nanoparticles and bacteria and the development of a pipelined suite of advanced optical techniques using the amplitude and the phase of the optical fields, multiple wavelengths, multiple scattering angles, polarization properties, and parallel interrogation volumes, which sequentially classify particle characteristics over a wide range of variables. The program will culminate in the deployment of a prototype in situ sensor network node that can measure both the physical and biogeochemical properties of aquatic nanoparticles forming the basis of a complete sensor network for in situ spatial and temporal monitoring.

This project, building a campus wide ultra high-speed optical fiber network that supports scientific application and experiments of high volume data, develops an experimental next-generation instrument to efficiently investigate and compare campus-scale terabit-class lambda network architectures that span from optical-circuits-only to packet-switched-only networks (and a range of hybrid combinations in between). Current commercial approaches to storage systems do not scale in either performance levels or data abstractions. The proposed approach builds on the foundation of the shared-nothing compute cluster emerging from data systems, visualization walls, and high-end instrument interfaces, having raw horsepower to serve and ingest high volumes of data required by applications. Constructing a next generation switch for simultaneously switching 10Gbs streams efficiently, the work aims at building a 21st century photonic instrument to explore the practical tradeoffs of network and application design in bandwidth-rich infrastructure. Supporting large scientific problems and enabling big simulations, the project constructs Quartzite, the experimental, next-generation instrument. While fostering comparative studies, Quartzite, a data-intensive application breadboard, enables stitching together resources, bringing them virtually in. Thus, this wavelength-selective switch creation, communication and delivery project, adds hybrid-networking structure to a unique campus-scale platform and enables the study of network architecture and application design in a band-width-rich infrastructure and the sharing of large data sets across clusters. The work involves high risk, with a promise of even higher impact, since data intensive scientific exploration can be brought into the scientists' lab, by using on-demand high-speed data flows to harness campus- to international-scale resources. The work explores the following issues:
How surplus of on-demand bandwidth can be exploited by end user applications,
How distributed systems can be best architected,
When is a non-shared packet network needed,
How should control of a hybrid fabric be handled,
Can applications truly exploit a high-speed parallel infrastructure,
Is dynamic reconfiguring of campus network to meet transient capacity demands practical,
Is it beneficial to expose direct circuits to individual endpoints, and
Do novel packet scheduling strategies for shared links dramatically improve the capacity.
Broader Impact: The Quartzite-enabled comparisons will influence the network structure of future research university networks, greatly increasing the capability for data-intensive research throughout the country. Working with industrial partners, the hybrid Quartzite core system and software will service us all.

A multidisciplinary team from the University of California, San Diego (UCSD), specializing in the fields of nanophotonics, nanooptics, optoelectronics, and material science and material processing are collaborating in developing Integrated Nanoscale Materials, Devices and Systems with special focus on Nanophotonics for Optical Delay Engineering (NODE). The aim of the project is to demonstrate chip-scale realization of multistage optical delay architectures using nanoscale photonic materials and devices in a waveguide configuration, taking advantage of the polarization degree of freedom. The largest thrust will be on investigation of resonant phenomena in nanophotonic optical components placed in proximity to each other and demonstration of their integration into Nanoscale Devices-and-System Architectures realizing programmable optical delays which are crucial for numerous applications including optical buffering for large optical data routing systems, true time delay phased arrays, and general digital optical signal processing architectures. Research efforts in methodology, design, fabrication and characterization of nanophotonic materials, devices and systems will be useful for students and researchers in the fields of nanophotonics, advancing the fundamental understanding of the near field resonant and nonresonant interactions between nanoscale devices, and enabling their effective integration with novel functionalities. We will also establish innovative education and outreach projects with the UCSD's Preuss School, designed for students in 6-12 grade coming from disadvantaged households.

NIRT: Opto-Plasmonic Nanoscope
Yeshaiahu Fainman, University of California at San Diego
0608863

Abstract

Intellectual Merit: This NIRT project focuses on the novel Opto-Plasmonic Nanoscope based on the recently observed transfer of the spatial phase of an ultrashort optical pulse into the phase of the excited surface plasmon polariton (SPP) wave packet. The Opto-Plasmonic Nanoscope resolution is determined by the SPP wavelength, which can be as much as 100 times smaller than the optical field wavelength, supporting resolution <100nm. The goal of this multidisciplinary proposal is to conduct basic research on the excitation, propagation, and detection of ultrashort pulse SPP waves focused to <100 nm, and to investigate effects that arise in the process of linear and nonlinear interaction of the focused SPP with bio-matter (e.g., protein molecules and live cells) attached to the surface. Specific research objectives include (i) excitation of SPP waves using 2D nanostructures for focusing to <100 nm; (ii) investigation of interaction of the SPP waves with various types of bio-matter arranged in different patterns on the surface; (iii) investigation of imaging and detection methods associated with the Opto-Plasmonic Nanoscope; (iv) investigation of label-free detection of protein molecules attached to the surface; (v) investigation of imaging of live cell dynamics on the surface with a resolution <100 nm; and (vi) planning innovative education and outreach projects with the Preuss School on the University of California, San Diego campus.

Broader Impacts: The research on the Opto-Plasmonic Nanoscope advances fundamental understanding and the ability to excite, control, and detect the SPP fields, and understanding of their interaction with biopolymers and live cells that has profound significance for the biomedical imaging. The proposed work will allow application of the SPP waves for advanced nanoscale biochemical, biological and medical imaging, and for sub-wavelength lithography. Innovative education and outreach projects with the Preuss School, designed for students in 6-12 grades coming from disadvantaged households will be carried out.

Objective: We propose to study Optical Parametric Oscillator (OPO) laser sources for the 3 um to 12 um band fabricated as monolithic on-chip nanowaveguides using standard lithographic tools.
Specifically, we propose an OPO that (1) is implemented as a monolithic, lithographically defined waveguide with integral Bragg reflectors;
(2) employs form birefringent structures for phase matching; and (3) has a triply resonant cavity. The combination of all three of these elements is necessary to create inexpensive and efficient OPO sources.

Intellectual Merit: To the best of our knowledge, phase-matched form birefringent waveguides have not yet been exploited in resonant nanocavities to create OPOs. Triply resonant OPO cavities also, to the best of our knowledge, have not been realized, and even doubly-resonant devices are relatively recent. Therefore the proposed research is transformative in nature as it will advance the fundamental understanding of (1) parametric oscillation in multiply-resonant form-birefringent waveguide cavities, (2) materials and processes that may be suitable for mass fabrication of such cavities, leading to on-chip mid-infrared OPO laser sources, and (3) numerical modeling of nonlinear interaction in resonant cavities, and numerical optimization methods relating to the design of multiply-resonant structures.

Broader impact: The development of the proposed compact and inexpensive on-chip mid-infrared source will lead to advances in spectroscopic instrumentation, with applications to environmental science, pollution monitoring, chemical threat detection and other areas. The project will also play a significant role in the education, outreach and development of human resources in science and engineering at the graduate and undergraduate levels.

Proposal #: CNS 09-23523
PI(s): Papen, George Fainman, Y.; Vahdat, Amin M.
Institution: University of California - San Diego
La Jolla, CA 92093-0934
Title: MRI/Dev.: Development of a Scalable Energy Efficient Datacenter (SEED)

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

Project Proposed:
This project, building a Scalable Energy Efficient Datacenter (SEED), develops an integrated solution that encompasses physical layer hardware, protocols, and topologies that can provide the expected size and performance scaling for future data centers while minimizing the cost and energy per switched bit. The work creates the knowledge base required for the development of next generation scalable, energy efficient datacenters. Unique features of this instrument include novel statistical multiplexing modules to reduce connection complexity, a circuit switched optical interconnection fabric, and the ability to accommodate novel protocols, components and subsystems in a realistic system environment. With a design based entirely on commodity components and a non-blocking and scalable switch, the baseline configuration of the SEED instrument will connect more than 250 servers, each operating at 10 Gb/s. The fully configured instrument is a hybrid electrical packet/optically circuit-switched network designed to efficiently route large data flows into a circuit-switched optical core utilizing an optical switch from a previously funded MRI, Quartzite. The instrument supports several newly established multidisciplinary projects including the ERC Center for Integrated Access Networks (CIAN), the MRI GreenLight project, the Center of Interdisciplinary Science for Art, Architecture, and Archaeology (CISA3), and projects at the San Diego Supercomputer center. Specifically, SEED is expected to create the technology base for an order of magnitude improvement in both the cost and energy per switched bit. This will be accomplished by the development of new protocols and topologies, measuring and optimizing application dependent traffic patterns, providing critical system-driven specifications of a technology roadmap for the development of novel photonic technologies, and acting as a platform for training the next generation network engineers that are equally versed in both optical and electrical networks. The following four issues are associated with the SEED instrument.
- Design of flow scheduling techniques for fat trees that fit both electrical and hybrid systems,
- Algorithms for fault tolerance (components in large scale communication switches fail),
- Optimal Wavelength Division Multiplexing (WDM) design (uses multiple lasers and transmits several wavelengths of light (lambdas) simultaneously over a single optical fiber)
- Technology road map based on findings on performance metrics pertaining to building, testing, and operating the initial optical aggregation, transmission, and switching hardware to inform the Center for Integrated Access Networks (CIAN) ERC.

Broader Impacts: The engine of the 21st century economy, the creation of wealth through information processing, utilizes data centers as its cornerstones. Hence, technologies that can enable larger and more energy efficient information processing will affect many, if not every, aspect of modern life. Access to efficient remote processing should dramatically reduce the amount of physical transport and avoid the expense and human costs of unnecessary commuting, minimize environmental impact from infrastructure and pollution, substantially reduce our dependence on energy imports, improve educational opportunities, enhance the distribution of medical services, and increase overall national security. Thus, the infrastructure to carry these services constitutes a precious national resource, perhaps as precious as the air, rail, and road transportation. Indeed, it should enable this country to better compete globally.

Objective:
The objective of this work is to the study of the Purcell effect in submicron metallo-dielectric submicron laser cavities.

Intellectual Merit:
The proposed research will investigate the spontaneous emission rate of a laser when optical modes are sustained in a very small cavity. The PI proposes to characterize the effect novel submicronlaser cavities by measuring the spontaneous emission rate under a range of conditions, varying temperature, size, material, cavity design and pumping schemes.

Broader Impact:
The advancement of nanolasers will enable compact sensing instruments and impact multiple fields such as environmental, chemical sciences and homeland security. In addition the project will help train and educate both graduates and grade students through research and outreach programs lead by the PI who has an exceptional record in the dissemination of research finds.

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)"


Abstract
The objective of this research is to study fundamental electronic, photonic, chemical, and bio-logical behaviors of nanoscale structures relevant to future applications in next generation storage, energy harvesting, communications and computing, quantum communication and information proc-essing, superconductivity, and biomedical and biochemical sensing. The approach is to utilize nano-scale e-beam lithography in conjunction with other nanomanufacturing technologies to fabricate and characterize nanometer scale metamaterials, devices, and subsystems in which these new behaviors are expected to manifest themselves most clearly and can be exploited.
Intellectual merit: The proposed acquisition will enable investigation of smaller structures, finer features, and larger patterns than can be experimentally accessed today. Electronic and spin dif-fusion, a variety of magnetic behaviors, structural and chemical changes, superconducting decoher-ence, and many other phenomena that occur at nanometric length scales in common materials will be explored. Research projects are also planned in the areas of nanophotonics, metamaterials, quantum optics, quantum information, and nanomedicine.
Broader Impact: The creation of wealth through advances in nanoscale science and technol-ogy is at the heart of the 21st century economy. The impacts span multiple technical fields, including information systems, health care, energy, pollution monitoring, and chemical threat and explosive detection for homeland security applications. The UCSD Nano3 facility is serving a wide area of Southern California, and the proposed tool will benefit users throughout this geographic area. The project will also play a significant role in promoting education and development of human resources in science and engineering at the graduate and undergraduate levels, diversity and outreach.

The objective of this research is to develop a state-of-the-art photonic chip-scale probing solution for integrated Si-photonics testing and to enable new multidisciplinary collaborative projects in nano-photonics and opto-electronics. The approach exploits a universal electronic-photonic probing station that integrates electrical, optical far-field, and optical near-field probes for electrical and optical interfacing to integrated circuits and to individual elements within such circuits, together with a full set of external optical and electronic instrumentation to provide an affordable, zero-capital-investment testing capability for Research and Development by academic, industry and government laboratories.

The intellectual merit of this versatile and user friendly Si-Photonics testing instrument includes basic research to identify new phenomena, inventing new photonic technology and creating new applications, as well as providing tremendous benefit to small businesses, various research institutions and government laboratories in their product development efforts. Moreover, it can serve as a testbed for development and reduction to practice of new approaches for efficiently probing and testing Si-photonic chips, gradually evolving to become industry standards.

The broader impact of the instrument spans multiple fields, including information systems, high speed electronics and photonics, and future computer science and engineering to create wealth for 21st century economy by advancing integration of nanoscale photonic, electronic and biomedical science and technology. It will provide service to industry in Southern California and play a significant role in the education and development of human resources in science and engineering at the graduate and undergraduate levels helping to train future engineers.

Fundamental Investigations of Nanolaser Physics: Statistical Properties, Thermal Stability, and Temporal Dynamics of Light Emission

Nanoscale lasers, with dimensions smaller than their operating wavelength, have the potential to offer unprecedented communication, sensing, and illumination functionalities, due to their incredibly small footprint and energy budget. However, the fundamental properties of nanolaser light emission are poorly understood, in particular their statistical properties. The objectives of this research are to develop a theoretical model describing the dynamics of nanolasers based on a rigorous set of measurements and to demonstrate electronically controlled nanolasers operating at room temperature. These nanoscale lasers would find applications in quantum communications and computation networks for secure communications and for modeling of complex systems like the Earth's climate. In addition, nanolasers have the potential for sensing bio-chemical agents in extremely small volumes for healthcare applications.


The overall significance of the proposed effort is to further advance the fundamental knowledge of nanoscale lasers. Nanolasers, which are formed from metallic, insulating, and semi-conducting materials, have temperature-dependent properties. The thermal stability of these lasers is intricately coupled to their emission properties. Additionally, the light emission and thermal properties generally evolve in time. Therefore, a theoretical model describing the dynamics of nanolasers, coupled with their statistical and thermal characteristics will be developed. The Purcell effect in quantum dissipative systems will be investigated to describe the sub-threshold behavior in nanolasers. Experimental objectives of this project include the design and analysis of second and/or higher order coherence measurements tailored for semiconductor telecom wavelength nanolasers at various temperatures. Electrically pumped coaxial nanolasers for continuous wave operation at room temperature will be fabricated and characterized. Results of these experiments will lead to construct more accurate models of nanolaser dynamics.

PI: Fainman, Yeshaiahu
Proposal #: 1445158
Institution: University of California-San Diego
EAGER: Cartridge lab-on-chip (CLOC) for Mobile Health

Mobile health (mHealth) uses mobile technologies for health research and healthcare delivery in concert with the more general electronic health concept which encompasses a wide range of services that are at the cutting edge of healthcare and information technology, including access to electronic health records, electronic prescribing, telemedicine, and health informatics.

The realization of a portable, affordable medical diagnostic platform will have a profound impact on the global level. The proposed research will not only advance the basic science and technology of lab-on-a-chip (LOC) systems, but will also lead to the development of additional LOCs that do not require external optical components.

This project will design and develop a smartphone interface system that would enable rapid, sensitive, specific, and reliable measurements with simultaneous detection using a medical sensing and diagnostic platform (MSDP) with a disposable cartridge lab-on-a-chip (CLOC) biochip. For integration with advanced mobile platforms They will utilize Google's open hardware platform, Project Ara, exploiting Java programming language which is commonly used by all mobile smartphone companies, including Google's Android. This device will include the use of an inexpensive, single use, disposable and universal CLOC that would be available in both developed and developing countries. The MSDP will perform detection on-chip, obviating the need for bulky detection equipment, paving the way for a truly portable medical diagnostic add-on for future smartphones.

? DESCRIPTION (provided by applicant): The overarching goal of this proposal is to push the depth penetration of multiphoton microscopy targeting neuroscience applications in need of large-scale recording of cortical activity where high resolution requirement (in the order of singl microns) cannot be relaxed. To achieve deep high-resolution imaging while retaining sufficient signal-to-noise ratio of the measurements for imaging of activity (e.g., for detection of single spikes induced calcium transients), we will develop an unconventional non-degenerate 2-photon microscopy capitalizing on the recent practical demonstration of the advantage of using long wavelength light (~1700 nm) for deep penetration 3-photon microscopy but circumventing the low probability of 3-photon absorption (3PA). Our deliverables - complementary to engineering efforts elsewhere aimed at large-volume sampling - would have a transformative impact on our ability to reconstruct spatially distributed neuronal circuit activity providing unprecedented opportunities for tests of biological hypotheses that are currently unfeasible. The seed of the new technology is a well-known phenomenon where absorption of the second photon by the fluorophore molecule is enhanced through an intermediate state induced by absorption of the first photon. This warrants an increase in the excitation efficiency given the right combination of the wavelengths. For our goal of deep penetration, the IR beam will deliver high photon flux to the focal volume inside the cortical tissue. The second higher energy photon beam will have lower intensity. Thus, while the higher energy photon beam would experience higher scattering in the brain tissue, the flux requirement for this beam will be relaxed (compared to that in the conventional 2-photon microscopy) helping to achieve deep imaging. Importantly, by increasing the intensity of the IR beam while lowering the intensity of the shorter wavelength beam, we will decrease the unwanted out-of-focus excitation on the brain surface. This is because the shorter wavelength beam will not have enough photon density at the surface while the IR beam will lie outside the degenerate 2- photon absorption (2PA) range for visible emission fluorophores. Finally, we will implement an innovative Adaptive Optics strategy to correct the phase distortions that will be experienced by the beam delivering higher energy photons. Specifically, we use the IR beam, which can be focused well deep inside the tissue, as a reference point (guiding star) and adjusting the phase of the second beam to reach the maximum overlap. Overall, we expect to achieve ~1.6 mm penetration inside the cortical tissue while avoiding excessive laser power and retaining the excitation volume characteristic for 2PA of the IR beam alone in the degenerate excitation mode. Our endpoint deliverable will be a prototype device with the proof-of-concept demonstration of its performance for imaging of brain activity in vivo using synthetic calcium indicators and genetically encoded calcium-sensitive fluorescent proteins. This project will lay the groundwork for an academic-industry partnership proposal in 3 years to fully develop and deploy the new technology as a commercial product.

The San Diego Nanotechnology Infrastructure (SDNI) site of the NNCI at the University of California at San Diego offers access to a broad spectrum of nanofabrication and characterization instrumentation and expertise that enable and accelerate cutting edge scientific research, proof-of-concept demonstration, device and system prototyping, product development, and technology translation. Nanotechnology is the cornerstone of many industry sectors and a rich source for scientific discoveries and innovations. Using nanotechnologies, scientists are likely to find solutions for the most important challenges in health, communications, energy, and environment. Nanotechnology is multidisciplinary by nature and requires highly sophisticated tools and deep expertise, often unavailable or unaffordable by individual research labs and businesses. The SDNI site will offer state-of-the-art knowhow, tools, and services of nanotechnologies to all interested users across the nation in a user friendly, timely, and cost effective manner. The site will also become a nanotechnology provider to create and develop new nanotechnologies and bring them to its users. The goals of the site are to serve a large number of academic, industrial, and government users, to transfer enabling nanotechnologies from research laboratories to the general user community, to educate and train future generations of scientists and engineers in nanotechnology, and to bring nanoscaled research experience to college students and K-12 students, especially underrepresented minority students, to prepare them for STEM careers.

The SDNI site will build upon the existing Nano3 user facility and leverage additional specialized resources and expertise at the University of California at San Diego. The SDNI site is committed to broadening and further diversifying its already substantial user base. The proposed strategic goals include: (i) providing infrastructure that enables transformative research and education through open, affordable access to the nanofabrication and nanocharacterization tools and an expert staff capable of working with users to adapt and develop new capabilities, with emphasis in the areas of NanoBioMedicine, NanoPhotonics, and NanoMagnetism; (ii) accelerating the translation of discoveries and new nanotechnologies to the marketplace; and (iii) coordinating with other NNCI sites to provide uninterrupted service and creative solutions to meet evolving user needs. Significant growth is anticipated in the number and variety of local and regional users in the academic, government, and industrial sectors. Discoveries made by users of the SDNI site have the potential to create transformative change in fields as diverse as medicine, information technology, transportation, homeland security, and environmental science, leading to improved healthcare, faster communications, safer transit, and cleaner water and air. To develop a more diverse and productive scientific workforce, the SDNI site will expand undergraduate and graduate training programs including REU opportunities to train 900 students over five years. Through an RET program and other activities, the site will work to increase the number of students from underrepresented minority groups who pursue studies and, ultimately, careers in STEM disciplines.

Abstract title: Exploring the Frontier of Photonic Device Size, Speed, and Efficiency Limits with Gain-enhanced Multifuncional Metamaterials

Abstract:
(Non-technical)
Metal-dielectric composites hold significant promise as the building blocks of next-generation information, communication, and sensing systems. The combination of metals and dielectrics offers unprecedentedly small volumes, fast speeds, and enhancements to nonlinear effects in photonic devices such as light sources, waveguides, and switches. Generally, however, the incorporation of metals necessarily increases the energy dissipated as heat in such devices, consequently reducing the energy carried by useful signals. We propose to create metal-dielectric and metal-semiconductor composites with the primary goal of demonstrating optical signal transmission without energy loss. Semiconducting materials may be engineered to emit and absorb light over a very broad color range, and their properties may be tuned by external electronics. We aim to develop the theoretical underpinning and experimental knowledge on the role of active semiconductors in enabling propagation of optical signals without loss of energy, while still retaining the small footprint and fast operation of the metal-dielectric-based photonic devices. We additionally plan to explore, both theoretically and experimentally, the enhancement of nonlinear effects in such devices, due both to the local enhancement of electromagnetic fields and to the cascaded nonlinearities present at the interfaces between the constituent materials.

(Technical)
Hyperbolic metamaterials offer unique and enhanced functionalities compared to conventional optical materials. For example, hyperbolic metamaterials exhibit highly localized electric fields in deeply subwavelength volumes, enabling field-enhanced nonlinear polarization, as well as broadband Purcell enhancement of the spontaneous emission rate. By introducing external strain, the band-structure of the constituent materials can be further modified, enabling multi-scale engineering of the hyperbolic metamaterials's linear and nonlinear optical responses. Unfortunately, hyperbolic metamaterials typically suffer from considerable Ohmic losses, preventing their applicability to practical devices. To overcome this deficiency, optical gain may be introduced for improved device performance. To date, most research on gain-compensated metamaterials has focused on dye molecules as a gain medium because they are easy to incorporate in proof-of-concept experiments and can be accurately modeled using simple two-level systems. In contrast, inorganic semiconductors and their heterostructures are attractive as gain media because their absorption/emission resonances may be engineered from terahertz to ultraviolet frequencies. Additionally, semiconductor hyperbolic metamaterials may be electrically injected with charge carriers, allowing for a more direct and reliable control of their functionality. And lastly, inorganic semiconductors offer distinct advantages over dyes in terms of robustness, lifetime, and integrability with guided wave devices. The overall goal of this proposal is to advance the science and technology of Gain Enhanced Multifunctional Metamaterials. Specifically, we aim to comprehensively understand and experimentally demonstrate: (1) lossless propagation in waveguide-based Gain Enhanced Multifunctional Metamaterials, (2) field-enhanced second- and third-order nonlinear effects in Gain Enhanced Multifunctional Metamaterials, and (3) strain-enhanced nonlinear effects in Gain Enhanced Multifunctional Metamaterials, all mediated by semiconductor gain. For specificity, we focus on the near-infrared part of the spectrum, but we stress that the lessons learned from our work may easily be extended to ultraviolet and terahertz frequencies alike.
Gain Enhanced Multifunctional Metamaterials offer an avenue for achieving unprecedented nonlinear conversion efficiencies with lossless signal transmission. Due to their extremely small footprint and potentially fast operation, Gain Enhanced Multifunctional Metamaterials will become strong candidates for integrated nonlinear devices of future photonic circuits. The proposed research will not only advance the basic science and technology of active semiconductor metamaterials, but will also set an example for the investigation of physical phenomena in which the self-consistent treatment of electronic, electromagnetic, and mechanical interaction becomes crucially important. We anticipate that Gain Enhanced Multifunctional Metamaterials will find applications in data- and telecommunications, graph-processing, computation, biomedical imaging, and chemical sensing.

Amidst today's data explosion, demand for computing power is accelerating, and the energy requirements for solving critical problems in science, engineering, business, and intelligent processing are increasing dramatically. In order to address this critical issue, the scientific and engineering community is beginning to explore new approaches to computing, such as mimicking the brain's structure or the dynamical behavior of coupled particles. However, implementing these approaches with conventional computer architectures is highly inefficient from both energy and computing standpoints. As a result, there is a pressing need to develop revolutionary computer architectures that overcome these severe roadblocks. An ambitious program is to be pursued within the framework of this project in which light, rather than electrons, is used to realize new computing paradigms with superior energy scalability. Specifically, computing architectures will be explored that exploit the wave nature of light (i.e., its amplitude and phase) harnessing the remarkable advancements over the past decade in nanofabrication of complex photonic chips with thousands of high-performance devices. These photonic platforms would have the potential to be computationally powerful, operate with unparalleled energy efficiency, and are scalable and highly reconfigurable.

To fulfill this vision of energy efficient photonic computing, the proposed research efforts will focus on the following two types of photonic processors: (1) Ising Machine and (2) Neuromorphic Computing Machine. The unifying aspect of these photonic processors is that they consist of dynamic networks of coupled photonic units and rely on the wave nature of light to solve problems which has no analogy in electron-based computing systems. Beyond developing new types of optical processors, photonics technology will be developed as the cornerstone of future computer systems. A novel architecture will be explored that integrates photonic processors and interconnects with electronic memory and processors to maximize the benefits of each technology. Research will also be undertaken to map complete, challenging problems to combinations of photonic accelerators and electronic processors, and to determine how to best scale them to maximize full-system performance. By innovating at all levels of the system - from devices to architectures including systems, compilers, and algorithms - the project would aim to achieve advances that cannot be realized within any single field.

Abstract:
(Non-technical)
A laser radiation with long wavelengths in the range has never been demonstrated even though it has a wide range of applications. Its usefulness makes its generation, manipulation and detection a critical task faced by the photonics community. There has not been any research on the guided wave approach to the generation, manipulation and detection of radiation in the long wavelength range of 20-60 micrometers, and therefore we feel that the proposed research will help to start this new and exciting field. To achieve the overarching goal on creating long wavelength radiation, its manipulation and detection on a chip, we aim to identify materials and construct optical difference-frequency generating devices, develop compact laser sources for difference-frequency generation, and construct integrated long wavelength signal processors on a chip. The ability to generate, manipulate and detect long wavelength radiation on a chip will have a significant impact on numerous applications including absorption spectroscopy, imaging and optical communications. The proposed research will not only advance the basic science and technology of chip-scale integrated far infrared radiation systems, but will also enable exploration of novel applications in biology, chemistry, security, physics, and astronomy. The project will provide scientific training for students at graduate and undergraduate levels as well as contribute to outreach, education and collaborative efforts with San Diego middle and high schools. Through our relationships with the Sweetwater, Preuss, and High Tech High Schools, we will continue to successfully engage students of diverse ethnicity, gender and economic backgrounds in Science, Technology, Engineering and Mathematics (STEM).
(Technical)
Radiation with wavelengths ranging from 20 to 60 micrometers has a wide range of applications in such fields as biology, chemistry, security, physics, and astronomy. Its usefulness makes its generation, manipulation and detection a critical task faced by the photonics community. The state of the art of the technology in this spectral range of optical radiation is in embryonic state with the current research focused on free space realizations. The generation of long wavelength radiation typically exploits frequency mixing using near-infrared laser sources and produces power levels of about tens of nanowatts, limited by phase matching and corresponding interaction length for free space implementations. Moreover, efficient detection of long wavelength radiation also imposes a critical challenge. It is evident that guided wave realizations on a chip will have a huge impact on advancing photonics in long wavelength spectral range because it allows engineering hybrid material structures with large nonlinearities and transparency, which together with engineering phase matching will enable efficient generation, transmission and detection of long wavelength radiation. The overall goal of this proposal is to establish chip-scale integrated technology for generation, manipulation and detection of optical radiation in the wavelength range of 20-60 micrometers. Specifically, our objectives aim to comprehensively understand and experimentally demonstrate: (1) various material platforms with properties necessary for transmission and efficient difference-frequency generation compatible with chip-scale realizations, (2) characteristics of the down-selected materials, including their nonlinear damage thresholds, (3) compact laser sources for difference-frequency generation in selected materials, and (4) designs and fabrication methodology of guided wave configurations with engineered phase matching for efficient generation and detection of the long wavelength radiation. The proposed chip-scale integrated long wavelength processors will have a significant impact on numerous applications including absorption spectroscopy, imaging and optical communications. The proposed research will not only advance the basic science and technology of chip-scale integrated far infrared systems, but will also enable exploration of novel applications in biology, chemistry, security, physics, and astronomy.

Nontechnical description: The ongoing explosion in generation of big data relies on development of new information processing techniques and technologies that can compute and communicate large volumes of information with unprecedented speed. The current trend in achieving such performances depends on seamless integration of electronics and photonic (optical) technologies. However, the state of the art photonic technologies are costly, bulky, fragile in their alignment, and difficult to integrate with electronic systems, both in terms of cost effective manufacturing and in terms of delivery and retrieval of massive volumes of data that photonic circuits can process. To overcome these deficiencies, the current trend emphasizes the construction of photonic subsystems directly on an electronic processor chip, with the same manufacturing process as the surrounding electronics. Development of photonic materials with substantial nonlinear characteristics is essential for the construction of integrated, high speed photonic devices and systems for ultrafast information processing of big data. The project provides scientific training for students at graduate and undergraduate levels as well as serves as a platform for outreach, education and collaborative efforts with middle and high schools. Engagement of students of diverse ethnicity, gender and economic backgrounds in Science, Technology, Engineering and Mathematics (STEM) is enabled through various ongoing student and teacher training activities.

Technical description: Optical materials with large second-order nonlinear susceptibilities are essential for the construction of integrated, CMOS compatible, high speed photonic devices for ultrafast on-chip modulation, switching and wave mixing of optical fields. Such nonlinear optical materials can be constructed by engineering the electronic band structure of semiconductors via either fixed charges at dielectric/semiconductor interfaces or gradient of work functions at metal/semiconductor interfaces. This project focuses on the design, fabrication and testing of nonlinear metamaterials, in free-space and guided wave configurations, for operation in the visible and near-IR regions. Additionally, relationships between the electrical and optical properties of the metamaterials are investigated in order to design electrically tuned optical nonlinearities for novel applications such as ultrafast switching. The overall goal of this project is to further advance nonlinear optical metamaterial science and technology, with focus on three specific approach objectives. The first objective focuses on theoretical analysis and modeling of metamaterials by engineering nanostructure composition exploiting various CMOS compatible materials; the second addresses development of nanofabrication methods of these metamaterials; lastly, the third objective targets experimental validation of the theoretical predictions and testing of the fabricated nonlinear metamaterials. This study also paves the way for development of numerous applications of metamaterials including modulation, switching, and wave mixing of optical fields. The PI continues to be committed to outreach, education and collaborative efforts within the university as well as with San Diego middle and high schools, through ongoing REU, RET and summer teaching programs.

This project will develop a multiwavelength surface-enhanced Raman spectroscopy (SERS) method for determining genomic mutations within specific genes related to antimicrobial resistance. The PI has published convincing preliminary results on extracting relevant information related to the composition of DNA strands from the measured SERS spectra. The ability to rapidly determining the genomic mutations within specific genes related to antimicrobial resistance would have a significant societal impact.mThe project will provide scientific training for students at graduate and undergraduate levels across several multidisciplinary fields, exposing them to advanced photonics, nanoscale fabrication, surface chemistry, and medical diagnostics.

The goal of this project is to develop the chemical resonance excitation wavelength selection (CREWS) method for determining genomic mutations within specific genes related to antimicrobial resistance (AMR). The proposed platform employs multiple excitation wavelengths to maximize the amount of data acquired from DNA using Raman spectroscopy, and uses advanced signal processing techniques to identify mutations within genes responsible for causing AMR. This technique provides an alternative approach to genomic mutation detection without the need for DNA sequencing, in which quick and efficient label-free detection of single point mutations in DNA strands can be performed.

As the Fourth Industrial Revolution is approaching, large-scale computing is becoming more demanding and popular than ever. However, the performance of conventional electronic microprocessors has almost reached their limits for device speed, on-chip density and power consumption and will not be able to continue sustaining the upcoming data explosion. Optical computation can be extremely fast and with low-power requirements compared to electronics, for its intrinsic high speed, large bandwidth, and unlimited parallelism, which are critical to ease the data traffic associated with applications where artificial intelligence decisions need to be made in real time. Novel approaches towards programmable computations are required for data-driven training of modern artificial intelligence. In this project, the investigators will leverage the state-of-the-art integrated photonics technology to develop an innovative programmable photonic computation accelerators (PPCA), accelerating the computation speed and reducing the cost and energy consumption to sustain long term performance requirements for machine learning. This research is closely integrated with the existing educational activities, providing both undergraduate and graduate students with the opportunity to participate in cutting-edge science and technology in an innovative way. The investigators also provide educational outreach activities in integrated photonic devices, machine learning, and computer algorithms to promote the interests and participations of K-12 students and broaden the participations from underrepresented groups.

Technical description:
With funding from the Electrical, Communications and Cyber Systems (ECCS) Division, the investigators from the University of Pennsylvania and University of California, San Diego are developing a disruptive system-level integrated nanophotonic circuits ? Programmable Photonic Computation Accelerators (PPCA) ? through active control via strategic engineering of quantum symmetry, to perform real-time programmable mathematical operations and implement machine learning algorithms. Unique symmetry-driven geometries will be explored to deliver novel topological photonic components required for matrix multiplication, which can be dynamically programmed by flexible control of spatial-variant optical modulation. On the developed programmable photonic computation accelerator platform, different iconic machine learning algorithms will be performed to demonstrate optical machine learning for the first time and test its corresponding speed and fidelity. The investigators have highly complementary expertise on active photonic circuits, integrated devices, systems, and packaging, as well as computation and machine learning, which will be actively synergized, enabling a paradigmatic shift towards system-level integration of large-scale photonic computation accelerators. If successful, the innovative programmable photonic computation accelerators could be applied in the domains which demand extreme speed, energy efficiency, parallelism, significant complexity, and high scalability on an ultra-compact footprint, and full programmability.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.