ABSTRACTS - STTR
This project is producing inexpensive, direct reading biosensors, capable of real-time measurement of bacterial contamination in sensitive areas, such as food and pharmaceutical facilities and water treatment plants. During Phase I, Protein Solutions demonstrated the feasibility of detecting ATP in quantities as small as 10-9 g (2xl0-12 moles) both visually and on photographic film. The technology employs the firefly luciferase catalyzed light producing reaction between luciferin and ATP. They are able to produce a spatial light pattern which indicates the concentration of ATP present in a sample. In this project they focus on increasing the sensitivity of the direct reading ATP sensor to levels more suited to bacterial detection (10-12 to 10-13 g). This increase in sensitivity is being achieved by three primary means: (1) increasing the intensity and/or duration of the luminescence for a given quantity of ATP; (2) increasing the amount of light that reaches the detector (film or otherwise); and (3) optimizing the non-instrumented detector for the system. Each of these objectives should contribute at least one order of magnitude increase in absolute ATP sensitivity.
The potential commercial applications as described by the awardee: Rapid, simple, inexpensive, and reliable measurement of bacterial contamination will facilitate industrial compliance with safe food and dairy practices. The sensors can also be applied to a range of medical and pharmaceutical environments and products. Eventually, marketing efforts will lead to consumer use in the home for the sanitary monitoring of kitchen and bathroom surfaces.
The chemical analysis of mixtures is commonly required in chemistry, materials science, biotechnology, and environmental science. If the application demands detection, identification, and quantification of more than a very few substances in a mixture, then chemical separation is usually required. Most current methods of separation are either very slow or are limited to only a small portion of the mixture. The objective of this research is to develop much faster instrumentation for the chemical analysis of moderately complex mixtures. The method employs two independent chemical separations applied in series to a mixture in such a way that the whole sample passes through both separations generating a separation in two-dimensions rather than one. The second of the two separations operates so quickly that it can be applied repeatedly to each small portion of the mixture emerging from the first separation. This method, comprehensive two-dimensional-gas chromatography, has been demon-strated in the research laboratory.
The potential commercial applications as described by the awardee: This research project will develop a rugged instrument for commercial application. The instrument will detect, identify, and quantitate volatile organic substances in mixtures containing about 100 components within five minutes or less.
This project is developing a capacitively coupled microwave plasma (CCMP) as a microsample excitation plasma for multi-element determinations with the detection limits, accuracy, precision, and sample size requirements of modern graphite furnace atomic absorption spectrometry, using atomic emission spectrometry. Currently, there are no widely applicable analytical methods for multi-element determinations on microsamples. In the unique CCMP approach the helium plasma supported on an electrode in the microwave field envelops a tungsten cup containing the liquid (2-10 microliters) or solid (ca. lmg) sample. The transient emission is detected with an echelle spectrometer using a Charge Injection Device (CID) detector. Detection limits are in the low pg range with 10 microliter liquid samples (0.5-5 ppb). Studies using the Thermo Jarrell Ash IRIS echelle spectrometer indicated that the CCMP is well suited for multi-element detection. Phase II will include the design of an optimum optical interface between the plasma and the echelle spectrometer, optimization of the CID data acquisition for transient signals, refinement in the electrode, redesign of the power supply to allow more reproducible computer control of the microwave field, and a comprehensive study of potential interferences in a variety of matrices, using both liquid and solid samples.
The potential commercial applications as described by the awardee: The unique combination of multi-element capability, high sensitivity, low cost, and ease-of-use results in substantial potential markets in clinical research, medical diagnostics, and routine laboratory analysis.
The design, fabrication, and testing of an innovative chemiluminescence (CL) based prototype analyzer capable of continuous chlorine monitoring in water is under development. Such an instrument permits precise control of chlorination processes reducing the health risks caused by the formation and release of chlorinated by-products associated with over-chlorination, particularly in drinking water. Current analytical instruments are poorly suited to this task due to interferences, unstable reagents, time-dependent responses, operator-dependent results, poor reproducibility, and expense. The CL analyzer will meet the need for a sensitive, accurate, highly selective, and inexpensive instrument that is easy to use with a minimum of operator intervention. This innovative new technology combines the intrinsic selectivity and sensitivity of CL with the reproducibility and ease of operation afforded by the use of solid phase modules for control of the pH, luminol concentration, and as a means to calibrate the analyzer. Solid phase beds eliminate the need for reagent preparation, and can be quickly and easily exchanged after long periods of operation (>30 days). Monochloramine, the most common interference in calorimetric analysis for chlorine, produces no CL response in the chlorine analyzer. Operation conditions, component hardware, solid phase bed design, and CL detection efficiency will be refined based on performance and commercial potential. Methods will be developed for quantitation of total chlorine and reagentless calibration. A prototype will be built and tested on real water samples forming the basis for commercialization of the technology.
The potential commercial applications as described by the awardee: Demonstration of the Reagentless CL Chlorine analyzer prototype will directly lead to the commercialization of this readily marketable technology. There is a need for this type of analyzer for process control in drinking water distribution systems and municipal wastewater systems throughout the country to mitigate the formation of chlorinated organic by-products due to over-chlorination.
This project addresses the technical merit and feasibility demonstration of novel integrated optical waveguide devices using the emerging technology of electro-optic polymeric materials. Such devices would offer significant benefits for optical communication, signal processing, computing and sensing applications. The overall objective of Phase I is to determine the technical merit and feasibility of incorporating an electro-optic polymer on a silicon substrate to form integrated optic waveguide devices. The program investigates both electro-optic polymers with established properties and electro-optic polymers at the forefront of development which have potential for improved performance. The polymers developed in the program in polymer research laboratories at the University of Cincinnati will be incorporated in the later stages of the device fabrication process. To demonstrate feasibility in this Phase I effort, new electro-optic organic polymers and novel opto-electronic device technology are being combined to demonstrate a commercially viable electric field sensor.
The potential commercial applications as described by the awardee: Applications include external modulation of lasers for communication and CATV, modulator arrays for data networks, optical network units in Fiber-to-the-Home, hybrid integration of silicon ICs and photonic circuits, A/D and D/A converters, voltage and electric field sensor.
The development of the polarization insensitive liquid-crystal Fabry-Perot (LC-FP) optical filter for wavelength-division-multiplexing (WDM) communication systems is investigated. It is well known that LC-FP is a high-performance filter due to its large tuning range, high finesse, and low voltage operations. However, because the modulation is based on the optical anisotropy, only the extraordinary wave can be modulated in the FP resonator. This results in a polarization sensitive filter that greatly reduces its "field application" in the WDM networks. Although polarization-diversity has been proposed and demonstrated to overcome this problem, it required polarization splitting/combining at the input/output ports and resulted what effectively constitutes two FP cavities. This increases packaging and production difficulties, making high-volume commercial device manufacturing impractical. This project, based on a new invention by the principal investigator, uses polarization optics to manipulate the arbitrarily polarized light in the FP cavity. By positioning the liquid crystal phase modulator in between crossed quarter-waveplates within the FP resonator the filter becomes polarization independent. The device structure is simple and mass producible. Successful completion of this STTR program can resolve the polarization-sensitive drawback of the LC-FP filter and widen its application in the WDM networks.
The potential commercial applications as described by the awardee: The primary commercial applications for this filter are the cable TV broadcasting, fiber-in-the-loop WDM networks, long distance telecommunication, and in the future all-optical networks. It can also be applied to spectroscopic analysis and fiber-based environmental sensor applications.
PD-LD, Inc. in cooperation with the ATC/POEM (Advanced Technology Center/Princeton Opto-Electronic Materials) of Princeton University, has recently developed a totally new method for the growth of thin films of complex organic compounds, called Organic Vapor Phase Deposition, OVPD. This new method was successfully used to deposit thin films of chemically pure DAST, a material with optical nonlinear properties among the best reported. On the basis of these results, PD-LD, Inc. with its President, Dr. Vladimir S. Ban as the PI and ATC/POEM with its Director, Professor Stephen R. Forrest as the Chief Adviser, are developing a prototype fiber optic modulator, based on thin films of DAST deposited by OVPD on a silicon optical bench configured for efficient coupling to optical fibers. This addresses for the first time the integration of waveguides of highly non linear organic materials with silicon optical benches, which might be populated with standard fiber optic components, such as laser diodes, detectors, optical fibers, etc. Thus, this project represents an important step toward the fully integrated opto-electronic integrated circuits (OEIC), where different materials will be combined for the optimal performance of various functions, such as light generation, light guiding, light modulating and light detection.
The potential commercial applications as described by the awardee: Markets for high performance fiber optic modulators are growing rapidly, and since DAST-based devices should have superior performance and lower prices than the competing products typically employing LiNbO3, PD-LD hopes to convert developments of this STTR into a very successful business.
This project demonstrates the feasibility of a continuous process of producing rugged, low moisture content, high bandwidth, gradient index plastic optical fiber. This type of fiber is expected to have great utility in high-speed local area networks. Existing Japanese production methods result in bandwidths which are three to ten times less than theoretically possible, and the bandwidth of the fiber is not stable and reproducible. The production rate is intrinsically limited by the batch nature of the process and/or multistep procedure. In the U.S., the High-Speed Plastic Network (HSPN) consortium was formed in 1994, and is supported by a $5M ARPA grant. A member of that team has licensed one of the Japanese batch technologies to fabricate the above type of fiber. The present project is to develop a novel, low cost, continuous production process for the fiber. The fiber will have a stable bandwidth of >2 GHz.km, be stable from -40oC to +150oC, have low moisture uptake, attenuation of less than 150 dB/kilometer and be stable to radiation exposure up to 103 Rad.
The potential commercial applications as described by the awardee: Local area networks have inadequate bandwidth for the anticipated needs in the coming years. Gradient index plastic optical fiber will be the most cost effective solution with adequate bandwidth. At present, there is no satisfactory production process for a rugged version of this fiber. The market is anticipated to grow to at least one billion meters per year.
Opto-electronic devices require materials with controlled environments surrounding individual active ions. The inability to achieve precise control lowers efficiency, creates damage sites, and reduces the overall reliability of the system. Inhomogeneities which cause the environmental changes result from two sources: impurities and self contamination. In many crystals this second factor is more significant than impurities. This project attempts to measure this self-contamination on a submicron basis. Crystals will also be grown to demonstrate control of this defect at the minimum levels possible. Scientific Materials has the ability to generate process control to the near millisecond level which relates to crystal growth on the atomic level. The techniques for evaluation of crystals are currently limited to the one micron scale. The work investigates the possibility of developing a submicron characterization system using NMR, EPR, or ODNMR imaging.
The potential commercial applications as described by the awardee: Commercial application is in the area of solid-state laser optical memories, holography, telecommunications, semiconductors, and nonlinear materials.
Network capacity is expected to grow more than an order-of-magnitude by the year 2000. To support this explosive growth new networking technologies are required. All-optical wavelength conversion and switching are two functions that have been identified as key building blocks for future high capacity networks. An integrated all-optical wavelength converter for use in all-optical switches and other applications is being developed. The effort will leverage Optivision's extensive experience gained from building and deploying optical crossbar switches based on semiconductor optical amplifiers and USC's cutting edge research in all-optical wavelength converters. Recently, wavelength conversion has been demonstrated with semiconductor optical amplifiers based on cross gain compression, cross phase modulation, or four wave mixing. The effort will begin by developing a set of switch requirements based on interaction with all-optical testbeds and high end users, then evaluating the various wavelength conversion techniques against these requirements. To demonstrate the feasibility of the approach, Optivision will perform both detailed modeling of the expected performance and a proof-of-concept experiment. They will also investigate the complexity and tradeoffs of fabricating integrated all-optical wavelength converters. The Phase II effort involves the fabrication, laboratory evaluation, and deployment into a testbed of integrated all-optical wavelength converters.
The potential commercial applications as described by the awardee: Integrated all-optical switching wavelength converters will be required in high capacity wavelength division multiplexed networks such as future cable television, telecommunication, and data transmission systems.
The performance of virtually all modern opto-electronic devices depends critically upon the ability to grow multi-layered, thin-film structures whose composition and thickness is precisely controlled. In production-scale deposition processes, these cannot now be monitored and adjusted in real time. Ion Optics will overcome the problem with a dual-light-source, fiber-optic, thickness and composition monitor operating simultaneously as an interferometer (measuring growth rate) and as a reflectometer (measuring composition and total thickness). A major advantage of such an instrument is its ability to provide the data needed to make instantaneous composition changes during growth to compensate for the effects of diffusion. Diffusion is an important factor when very thin adjacent layers of dissimilar composition must be deposited at relatively high temperature, as is the case for multiple quantum well devices. Phase I combines laser and white-light sources in a single diagnostic instrument compatible with high temperature processes, immune to electromagnetic noise (a by-product of rf wafer heating), and free of the requirement for precise optical alignment. The basic concept of the fiber-optic monitor has been demonstrated in rudimentary pulsed laser experiments on a silicon nitride reactor at Brown University; the principal investigator has successfully extracted real-time layer composition from white-light reflectance spectra. Phase I extends this earlier work to a practical dual-source configuration fast and accurate enough to track thin-film growth at rates typical of advanced devices.
The potential commercial applications as described by the awardee: Feedback control is key as new opto-electronic devices place greater demands on growth processes; the annual market for reasonably priced, easy to use thickness and composition monitors will be several million dollars. A less capable version would compete with quartz deposition gauges, with a market of tens of millions per year.
The research will develop thin film electroluminescent displays on plastic substrates. The zinc gallate (ZnGa2O4) phosphor host will be grown by metallorganic chemical vapor deposition (MOCVD) at £425oC on a high-temperature Kapton substrate. Luminescent centers will be introduced by ion implantation. Phase I will demonstrate that oxide phosphors can be deposited by MOCVD at temperatures compatible with Kapton, a plastic usable up to ª450oC. Because Kapton, and other polymide materials are not optically clear, structures having light emission from the top (nonsubstrate) side will be developed. Substrate temperature will be controlled by water cooling during ion implantation of luminescence centers. Glass substrates will be included as experimental controls. Spire will compare the quality of MOCVD-grown ZnGa2O4 films on plastic and glass substrates by x-ray diffraction and electron microscopy, and photoluminescence and cathodoluminescence tests will be performed on annealed ZnGa2O4 films. The University of Florida Department of Materials Science will then fabricate and test electroluminescent devices on both glass and plastic substrates.
The potential commercial applications as described by the awardee: This research will result in the capability to fabricate flat-panel EL displays on plastic substrates for rugged, bright, lightweight, hand-held information terminals to provide better graphical communication to personnel in demanding environments.
An imaging system based on ultra-wideband electric-field sensors is being investigated and developed. The device is based on a new opto-electronic design which is capable of time-domain far-infrared spectroscopy across a frequency range extending from near DC to several THz. Fundamentally, the electric-field sensor system is based on the linear electro-optic effect (Pockel's effect) in electro-optic crystals where a pulsed microwave signal acts as a transient bias to induce a transient polarization in the sensor crystal. This polarization is then probed by a synchronously pulsed laser beam, and the spatial and temporal electric-field distribution is projected onto a CCD camera by the laser. Previous studies of these sensors has demonstrated a sub-wavelength spatial resolution, femtosecond temporal resolution, near DC-THz bandwidth, sub-mV/cm field sensitivity, up to 100 Hz scan rate, and a signal-to-noise ratio better than 10,000:1. The electro-optic detection has a flat (nonresonant) spectral responsivity (from near DC to several THz), and an extended dynamic range (> 1,000,000). The simplicity of the detection geometry, capability for optical parallel processing, and excellent signal-to-noise ratio make this system suitable for real-time, 2-D coherent far infrared imaging applications.
The potential commercial applications as described by the awardee: Commercial applications of this research are in the areas of FIR spectroscopy, electric field sensor, and medical imaging.
This project describes two novel designs for diode-pumped, compact, efficient, blue laser sources. Such sources are needed in many applications including high density optical data storage, laser printing, and free space optical communication. Presently, such compact and efficient sources are not commercially available for these applications. The designs described in this project are based on upconversion lasing in rare-earth doped fluorozirconate (ZBLAN) glass fiber. The first is a Pr/Yb co-doped fiber which has previously been demonstrated as a laser operating at red, orange, green and blue wavelengths. The blue laser output power, however, was severely limited due to competing transitions from a common upper laser level. The solution to the problem is described and is being tested and developed for this project. The second upconversion blue fiber laser to be developed in this project is based on Tm doped ZBLAN fiber. This laser has also been demonstrated, but lacks a convenient, scalable, diode-based pump source for commercialization. In this project, a novel and efficient pump source will be developed and demonstrated. Prototype laser systems for each of the two designs mentioned will be constructed and tested for future development.
The potential commercial applications as described by the awardee: Applications of this research are in the areas of optical data storage, printing applications, free space optical communications, optical display, spectroscopy, flow cytometry, molecular biology, high performance imaging, and semiconductor inspection.
A novel approach for the fabrication of highly efficient Faraday-active optical waveguide structures is planned. Faraday-active waveguides are presently of great interest as their development is the critical enabling technology associated with the demonstration of all-fiber optical circulators. Such devices, which may be characterized as multipart nonreciprocal polarization rotators, provide a means by which the telecommunications rate may be immediately doubled on the existing optical fiber carrier infrastructure. Successful implementation will lead to full-duplex operation over "long haul" fiber carriers. The suggested circulator approach is passive, and does not therefore require external clocking controls. Separation of the signals is based only upon propagation direction; no additional losses are imposed on transmitted signals, as in the case of conventional directional couplers. The investigators use advanced thin-film techniques in the development of optical fiber segments. These processes have been previously shown to promote the introduction of photonically-active dopant species at dopant levels which are orders-of-magnitude greater than may be produced by conventional means. The technology will replace conventional bulk optics technologies; as waveguide structures with dramatically improved figures of merit will be developed and characterized during the initial Phase I period. The Phase I program also includes analysis of integrated permanent magnet structures, and a design assessment for optical circulator prototype development.
The potential commercial applications as described by the awardee: The development of high Verdet constant materials offers the potential for the achieving optical elements which double the throughput of fiber communication links. In addition, numerous other commercial uses exist for these materials.
This project investigates metal-organic chemical vapor deposition (MOCVD) to improve the performance of the blue-emitting layer used for full-color thin film electroluminescent (TFEL) displays. TFEL displays have demonstrated performance advantages compared with active matrix liquid crystal displays (AMLCDs) including wide viewing angle, wide operating temperature range, fast response time, and inherent ruggedness. Commercialization of TFEL displays has been impeded by the insufficient luminance and efficiency of the blue-emitting EL phosphor films. MOCVD has demonstrated the capability of growing crystalline binary and ternary sulfide phosphors at temperatures less than 600oC, eliminating the need for costly high-temperature substrates. Two approaches are being pursued for improving the blue EL material performance. The MOCVD process for the SrS:Ce phosphor is optimized for luminance and emission intensity in the blue spectral region. The addition of codopants are being investigated to compensate for SrS lattice defects. Secondly, MOCVD of cerium doped gallium sulfide is being investigated as a potential new blue EL phosphor. The best performing blue-emitting material will be selected for process scale to commercial size TFEL display panels in Phase II.
The potential commercial applications as described by the awardee: Potential commercial applications include full-color emissive flat panel displays for use in portable computers, industrial process control, instrument and medical electronics, and telecommunications.
Growth of highly electro-optic nonlinear materials can provide the key for enabling the production of efficient optical components such as tunable filters and modulators for optical communications. In addition, these devices can be used as a building block for systems including optical sensors and interferometers. Currently available nonlinear materials such as LiNbO3, BaTiO3, and PLZT do not have the necessary physical constants to make efficient devices in terms of power consumption and driving voltages required for operations. Strontium Barium Niobate provides materials with extremely large electro-optic coefficient (1380 pm/V for SBN:75 compared to 30 pm/V for LiNbO3) that can greatly improve the performance of exiting nonlinear optical devices and components. CoreTek, in conjunction with the University of New Mexico, is developing the technology needed to produce efficient SBN thin films based devices and components that would be directly useful in applications such as optical communications.
The potential commercial applications as described by the awardee: The research results will be applied in areas such as components for optical communication systems, sensors and interferometers for applications in industrial and environmental sensing, and opto-electronic switching devices.
Wavelength-selective filters in the integrated-optic embodiment are the most promising candidates for deployment in Wavelength-Division-Multiplexed net-works. A waveguide grating filter appears to be very promising on account of its extreme wavelength sensitivity and compactness. However, the performance of practical devices has thus far been severely limited by the lack of high-reflectance waveguide gratings. The unique feature of the described effort in achieving high-reflectance gratings is the use of a Si overlayer to substantially perturb the mode index of an optical waveguide underneath it and, yet, without adding substantial mode loss. Si has been selected on account of its large refractive index, processibility, and low cost. Within this framework, Advanced Photonics Technology envisions the development of a waveguide grating filter device with enhanced performance that can meet the needs of most complex WDM systems. This filter will then be coupled to an external laser source to form a hybrid optical module with tunable wavelength for a number of practical applications. This new technology, developed in conjunction with the University of Florida, will then be transferred to the company for further refinement to a precommercial level.
The potential commercial applications as described by the awardee: The primary commercial application of waveguide grating filters is in Wavelength-Division-Multiplexed networks. Another most important application is the development of compact and efficient waveguide lasers and amplifiers.
Recent major advances in Praseodymium (Pr)-doped fluoride glass fibers have made them the most desirable medium for fiber amplifiers and lasers at 1.3mm wavelength. The availability of prototype Pr-doped fiber amplifiers for 1.3mm wavelength-division-multiplexing (WDM) has heightened the need for 1.3mm lasers. Commercially available widely-tunable laser sources are typically based on grating-tuned external-cavity semiconductor lasers suitable only for laboratory environment. The requirement for 1.3mm tunable lasers that are fiber-compatible, robust, and cost-effective makes an all-fiber based tunable laser structure the best candidate. The focus of this program is the research and development of novel fiber Fabry-Perot tunable-filters (FFP-TFs) based on fluoride fibers (specifically ZBLAN fibers), and the application of FFP-TFs in the generation of high-power, narrow-linewidth, and wavelength-tunable Pr-doped ZBLAN fiber lasers in the 1.3mm wavelength region. These lasers will allow telecommunication systems to access an additional l00nm of frequency spectrum using standard 1.3mm single-mode fibers which have been widely installed throughout the world. In addition, the resultant work will enable broad-based ZBLAN fiber device technology development that can be extended to other wavelength regions, e.g., to tunable upconverted blue-green lasers and mid-IR lasers using appropriate dopants in ZBLAN fibers. Additional applications using such new tunable lasers span from holographic data storage (tunable blue-green lasers) and free space optical communication, to spectroscopy and environmental sensing (with tunable mid-IR lasers).
The potential commercial applications as described by the awardee: The research addressed will be applied to 1.3mm wavelength-division-multiplexed optical communi-cations, holographic data storage, and environmental sensing.
The feasibility of a novel architecture integrating light sensing and image processing functions on the same chip is being investigated. Specific image patterns can be learned by the circuits within microseconds. This information is stored in the synaptic connections on-chip and can be recalled at later processing stepsæeven from incomplete or noisy data. The system will be a co-processor by design. The intent is to assure not only compatibility but also high performance within a conventional computer architecture framework. Commercially available microprocessors and digital signal processors can thus be used to add on symbolic data manipulation capability for comprehensive systems. The work involves investigation of a locally connected neural architecture pioneered at the research institution and experimentation with prototype chips with on-chip CMOS light sensing diodes.
The potential commercial applications as described by the awardee: The project aims for technology insertion into conventional computers, which allows for applications in the near future in security systems, manufacturing automation, quality inspection, and smart sensors.