Principal Investigator: S.-T. Ho

Sponsor: National Science Foundation (NSF) CAREER Award, 6/95 – 6/99

This research program investigates novel quantum and nonlinear optical effects in nanofabricated optical structures for optoelectronic and photonic applications. Research topics include: (1) realization of novel microcavity semiconductor device structures and the study of quantum effects in such structures, including the modification and control of spontaneous emissions in nanometer-size optical waveguides and microcavities; (2) realization of novel optical Bragg structures at the 1.5-micron wavelength range in semiconductor waveguides to achieve ultra-broadband reflection; and (3) theoretical study and experimental demonstration of a new type of optical solitary wave called the Bragg soliton that exists in Bragg structures having third-order optical nonlinearities. This research could have substantial impact on a new area of quantum electronics called nanophotonics that utilizes the quantum effects of both the electrons and photons.

Co-Investigator: S.-T. Ho

Sponsor: NSF (Materials Research Center), 9/96 – 2/99

This is a collaborative effort with research groups in the Materials Science, Chemistry, and Physics Departments to study new materials for device applications. Current research projects include: (1) novel optical phase and amplitude modulators based on erbium-doped ferroelectric thin films; (2) potentially low-voltage, high-speed optical phase and amplitude modulators based on self-assembled organic polymers having very high electro-optic coefficients; (3) large-bandgap semiconductors; and (4) materials having strain-induced quantum dots / wires.

Principal Investigator: P. Kumar

Sponsor: Office of Naval Research (ONR), 3/98 – 3/99

This award allows the purchase of a diode-pumped, Q-switched, Nd:YAG laser with injection seeding and harmonic-generation options. The new laser replaces a flash-lamp pumped system used for over seven years in our ONR program "Quantum Optics with a Q-Switched Pump Source." It has higher peak power, less pulse-to-pulse energy fluctuations, and narrower linewidth. It significantly improves the dynamic range of our quantum-noise measurements of devices based on traveling-wave parametric interactions in bulk as well as guided nonlinear media. Our goal is to demonstrate turnkey sources generating squeezed twin beams and sub-Poissonian states of light. Such states have been shown to improve the sensitivity of key optical measurements beyond the shot-noise limit.

Principal Investigator: P. Kumar

Sponsor: ONR, 10/96 – 9/99

High pump power, a must for most nonlinear optical effects, is easily obtained with the use of a Q-switched laser. Recently, we have demonstrated that such a laser can be employed in quantum-optics experiments with great success. Unlike the case with optical cavities, quantum effects are observed in a single-pass traveling-wave type of interaction with a nonlinear medium, resulting in a large temporal bandwidth. Our approach to quantum-light generation has been followed in many laboratories around the world. We have demonstrated the generation of squeezed states of light, twin-beam states of light, and sub-Poissonian states of light. Using a setup that self-generates a matched local oscillator for the detection of squeezing, in 1994 we observed 5.8±0.2 dB of quadrature squeezing, which is still the highest to date for a single-pass traveling-wave experiment. In this program, we are conducting such proof-of-principle experiments that demonstrate the use of a Q-switched pump laser in the generation and application of pulsed twin-beams and squeezed states of light. In the past few years, our major thrust has been to perform pulsed sub-shot noise imaging experiments. In particular, we have demonstrated quantum correlations in images that have been parametrically amplified and performed experiments to show that noiseless image amplification is possible with optical parametric amplifiers.

Investigators: P. Kumar, S.-T. Ho, and B. Wessels

Sponsor: Defense Advanced Research Projects Agency (DARPA) / U.S. Air Force Multidisciplinary University Research Initiative (MURI), 6/96 – 5/01

We are developing novel, compact, integrated, optoelectronic and optical devices for use in ultrahigh-speed wavelength-division-multiplexed and time-division-multiplexed networks. The devices include: (1) fiber-optic parametric-amplification-based storage buffers, tunable pulsed oscillators, time-domain demultiplexers, clock extractors, and regenerators; (2) microcavity lasers, modulators,and multiplexers / demultiplexers; and (3) thin-film optically active waveguide modulators and amplifiers. These devices will be capable of operating at speeds approaching 1 terabit per second. A number of specific collaborative research projects are being pursued. The collaboration spans three academic disciplines and an industrial partner (a small business subcontractee).

Principal Investigator: P. Kumar

Sponsor: ONR and National Security Agency (NSA), 4/98 – 4/99

Following three successful international workshops held since 1990 in the general area of quantum communication and measurement, the fourth conference of the series was held at Northwestern University during August 22–27, 1998. It was devoted to exploring the physical, mathematical, and technical problems related to quantum noise and quantum information in open systems, particularly those in information processing, optical-communication networks, and quantum computing. The subject areas of the conference have tremendous potential impact on the practice of communication, computing, and cryptology. The conference allowed key researchers in experimental and engineering aspects of quantum optics and communication systems to interact with physicists and applied mathematicians working in the areas of quantum probability and measurement theory. The conference program was in the form of invited, regular, and poster papers. Proceedings of conference will be published by the Plenum Press.

Principal Investigator: P. Kumar

Sponsor: NSA, 6/98 – 6/01

An experimental / theoretical research program is underway with the goal of demonstrating a prototype nonlinear-loop mirror based on the cascaded second-order nonlinear c (2) effect in lithium niobate. A preliminary theoretical analysis showed that this phenomenon leads to an effective nonlinear index 1,000 – 10,000 times larger than the fiber nonlinearity. We aim to exploit this large nonlinearity by fabricating useful optical waveguide devices on lithium niobate substrates having dimensions in the order of a square inch.

Principal Investigator: P. Kumar

Sponsor: NSF, 2/98 – 4/01

This is an experimental program to develop an integrated lithium-niobate waveguide device for use as a reliable, compact source of highly-squeezed-light with relatively low-power mode-locked lasers. The experiments rely on traveling-wave degenerate second-harmonic generation and optical parametric amplification exploiting the c (2) nonlinearity of lithium niobate. These experiments are based on our analyses of traveling-wave degenerate c (2) interactions in which two indistinguishable fundamental-frequency photons and one second-harmonic photon participate. This is a collaborative project with Prof. M. Fejer of Stanford, who is fabricating and developing the required integrated, quasi-phasematched, low-loss, lithium niobate waveguides.

Principal Investigator: P. Kumar

Sponsor: U.S. Air Force Office of Scientific Research, 5/99-4/00

This grant is to purchase an ultrafast synchronously-pumped optical parametric oscillator. The instrument, which is a tunable source of sub-picosecond pulses in the 1.3--1.5, m m communication band, will be used to characterize novel all-optical devices, such as fiber-optic cache-memory buffers and optical regenerators, that are being developed to demonstrate optically-digital communication and processing at the quantum limit. Such devices will also be essential for deploying packet-switched ultrahigh-speed time-division multiplexed all-optical networks capable of operating at speeds in excess of 100 Gbs.

Principal Investigator: A. Taflove

Sponsor: Interstitial, Inc., 9/96 – 12/99

Finite-difference time-domain (FDTD) computational electromagnetics modeling is used to analyze and design a novel ultrawideband microwave sensor technology for the detection of early-stage human breast cancers. In addition, breast-imaging algorithms for this synthetic-aperture "tumor radar" are being developed for use in pre-clinical trials commencing in 1999.

Principal Investigator: A. Taflove

Sponsor: U.S. Army Research Office (ARO) / BSEI, Inc., 7/98 – 6/99

FDTD computational electromagnetics modeling is used to explore the target backscattering response of a proposed ultrawideband illuminating radar signal operating at millimeter wave frequencies. The backscatter is compared to that of a radar signal having the same absolute-bandwidth but operating at much lower microwave frequencies. In the latter case, the percent bandwidth is much greater and the radar is correspondingly more difficult to engineer. Adaptivity of the millimeter-wave illuminating signal to discriminate among target shapes is explored.

Principal Investigator: A. Taflove

Sponsor: Samsung, Inc. (Korea), 7/97- 12/99

FDTD computational electromagnetics modeling is used to evaluate potential electromagnetic wave radiation problems caused by very-high-speed digital microchips. Novel alternating-direction implicit FDTD algorithms are being investigated for modeling the microwave electromagnetic properties of VLSI chips having feature sizes of 0.1 micron.

Principal Investigator: A. Taflove

Sponsor: T&M Antennas, Inc., 7/98- 6/00

FDTD computational electromagnetics modeling is used to design advanced multiband antennas for handheld wireless communications devices. The new antennas are mounted within the plastic case of the handheld device, and hence eliminate the ubiquitous whip antenna. The design challenge is to achieve antenna performance comparable to current whips using a physically robust, low-cost, zero-profile, miniaturized case-mounted antenna. A patent application for a novel design of this type has been submitted to the U.S. Patent Office, and prototypes are currently being constructed and tested.

Principal Investigator: A. Taflove

Sponsor: US Army Breast Cancer Program, 5/99 - 4/02

Ms. Popovic is being trained in the use of ultrawideband impulse radar techniques for detecting and imaging small breast tumors.

Principal Investigator: A. Taflove

Sponsor: Motorola, Inc., 3/99- 6/00

A new undergraduate educational laboratory in wireless telecommunications has been established courtesy of a gift of equipment and other resources by Motorola. Initial use of the laboratory was in spring quarter 1998-1999 for the freshman Engineering Design and Communications course. Five student groups totaling 20 students designed, constructed, and tested UHF gain antennas for base stations and handheld portable operation. All five groups succeeded in their design goals. The laboratory was dedicated in May 1999 with several Motorola officials present, including CEO Chris Galvin and Vice President Bob Barnett.

Principal Investigator: B. Wessels

Sponsor: U.S. Department of Energy (DOE), 5/85 – 4/99

This is a fundamental study of the defect structure of semiconducting perovskite oxides prepared by metalorganic chemical vapor deposition. We examine the role of point and extended defects in determining the dielectric properties of ferroelectric thin films. Analysis techniques include X-ray diffraction, transmission electron microscopy, impedance spectroscopy, and polarization tests.

Principal Investigator: B. Wessels

Sponsor: NSF (Materials Research Center), 9/96 – 2/99

This project synthesizes and experimentally characterizes several new materials having the potential for constructing novel optical and electro-optical devices. The new materials include: (1) optically nonlinear ferroelectric-oxide thin films; (2) optically amplifying barium-titanate films grown by vapor-phase epitaxy and doped with rare-earth ions; (3) ferroelectric thin films integrated with silicon; (4) InAsSb thin films and heterostructures deposited by metalorganic vapor phase epitaxy; and (5) quantum-well and quantum-dot nanostructures having potential applications in mid-infrared and far-infrared lasers and photodetectors.

Principal Investigator: B. Wessels

Sponsor: NSF (Science and Technology Center for Superconductivity), 1/95 – 1/99

High-temperature superconducting thin films are being investigated for potential high-speed device applications. The material systems investigated include BiSrCaCuO and oxycarbonates. Films are synthesized by metalorganic chemical vapor deposition.

Principal Investigator: B. Wessels

Sponsor: National Aeronautics and Space Administration (NASA), 1/97 – 12/98

The project involves the optimization of wide-gap semiconductor thin films for solar-blind ultraviolet photodetectors.

Principal Investigator: B. Wessels

Sponsor: NSF, 7/97 – 6/99

The defect structure of epitaxial gallium nitride and other wide-bandgap semiconductors is under investigation to optimize their electrical properties. Of special interest are the factors that determine p-type conductivity. Measurement techniques include photoluminescence spectroscopy, transient photoluminescence, and photocapacitance spectroscopy.

Principal Investigator: H. Yuen

Sponsor: ONR, 10/95 – 9/98

This project studies the possibility of achieving exponentially accurate measurements, in particular quantum measurements, using only polynomial resources. Potential areas of application include ultrahigh-precision measurements in science and technology, as well as the development of super-supercomputers.

Principal Investigator: H. Yuen

Sponsor: Motorola Center for Telecommunications Research, 8/98 – 8/99

This project introduces the concepts and techniques of quantum identification and quantum cash. Important potential commercial applications include no-clone memory, secure smart cards, and secure general financial transactions.

*(For ease of identification, each citation in this and the following sections will begin with the group faculty member(s)’ name(s))

S. T. Ho, H. Cao, Y. G. Zhao, H. C. Ong, S. T. Ho, J. Y. Dai, J. Y. Wu, and R. P. H. Chang, "Ultraviolet lasing resonators formed by scattering in semiconductor polycrystalline films," Applied Physics Letters, Vol. 73, p. 3656, 1998.

S. T. Ho, H. Cao, Y. Zhao, , E. W. Seelig, Q. H. Wang, R. P. H. Chang), "Random laser action in semiconductor powder," Physical Review Letters, vol. 82, p. 2278, 1999.

S. T. Ho and M. K. Chin, "Design and Modeling of Waveguide-Coupled Single-Mode Ring Resonators," Journal of Lightwave Technology, Vol. 16, No. 8, pp. 1433-1446, 1998.

S. T. Ho, D. M. Gill, G. M. Ford, B. A. Block, and B. W. Wessels, "Guided wave fluorescence in thin film Er-doped barium titanate," Proc. of the Materials Research Society, 1998.

P. Kumar, D. Levandovsky and M. Vasilyev, "Amplitude squeezing Of light by means of a phase-sensitive fiber parametric amplifier,'' Optics Letters, Vol. 24, No.14, pp. 984-986, 1999.

P. Kumar and G. S. Kanter, "Optical devices based on internally-seeded cascaded nonlinearities,'' IEEE J. of Quantum Electronics, Vol.35, No. 6, pp. 891-896, June 1999

P. Kumar and D. K. Serkland, "Tunable fiber-optic parametric oscillator,'' Optics Letters, Vol. 24, No.2, 1999, pp. 92-94, 1999.

P. Kumar, D. Levandovsky and M. Vasilyev, "Soliton squeezing in a highly transmissive nonlinear optical loop mirror,'' Optics Letters, Vol. 24, No. 2, , pp. 89-92, 999; errata: Vol. 24, No.6, p.423, 1999.

P. Kumar, G. M. D'Ariano and M. F. Sacchi, "Tomographic measurements of nonclassical radiation states,'' Physical Review A, Vol. 59, No. 1, pp. 826-830, 1999.

P. Kumar, D. Levandovsky and M. Vasilyev, "Perturbation theory of quantum solitons: continuum evolution and optimum squeezing by spectral filtering,'' Optics Letters, Vol. 24, No. 1, pp. 43-45, 1999.

P. Kumar, W. L. Kath, A. Mecozzi, and C. G. Goedde, "Long-term storage of a soliton bit

stream using phase-sensitive amplification: Effects of soliton-soliton interactions and quantum noise,'' Optics Communications, Vol. 157 (1--6), pp. 310-326, Dec. 1998.

P. Kumar, M. Vasilyev, S.-K. Choi, and G. M. D'Ariano, "Investigation of the photon

statistics of parametric fluorescence in a traveling-wave parametric amplifier by

means of self-homodyne tomography,'' Optics Letters, Vol. 23, No. 17, pp. 1393-1395, 1998.

P. Kumar, G. D. Bartolini and D. K. Serkland, "All-optical storage of a picosecond-pulse packet using parametric amplification: phase-insensitive loading," in Trends in Optics and Photonics Series, Vol. 25, Optical Amplifiers and Their Applications, D. Baney, K. Emura, and J. Wiesenfeld, eds., pp. 288-291,1998.

M. Plonus and Gerwe, D.R. , "Superresolved Image Reconstruction of Images Taken Through the Turbulent Atmosphere," Journal of Opt. Soc. Am., A, Vol. 15, No. 10, pp. 2620-2628. October 1998.

A.Taflove and V. Anantha, "Calculation of Diffraction Coefficients of Three-dimensional Infinite Conducting Wedges Using FDTD," IEEE Trans. Antennas and Propagation, Vol. 46, pp. 1755-1756, Nov. 1998.

A.Taflove, S.C. Hagness and J.E Bridges, "Two-dimensional FDTD Analysis of a Pulsed Microwave Confocal System for Breast Cancer Detection: Fixed-focus and Antenna-array Sensors," IEEE Trans. Biomedical Engineering, Vol. 45, pp. 1470-1479, Dec. 1998.

A.Taflove, S.C Hagness, and Bridges, J.E, "Three-dimensional FDTD Analysis of a Pulsed

Microwave Confocal System for Breast Cancer Detection: Design of an Antenna-array Element," IEEE Trans. Antennas and Propagation, pp. 783-791, May 1998.

B. Wessels, G-C. Yi, B.A. Block and G.M. Ford, "Luminescence Quenching in Er-doped BaTiO₃ Thin Films,"Applied Physics Lett., Vol. 73, pp. 1625-1627, 1998.

B. Wessels, "Ferroelectric Oxide Epitaxial Thin Films: Synthesis and Non-Linear Optical Properties," J. Crystal. Growth, Vol. 195, pp. 706-10, 1998.

B. Wessels, K.-W. Chang, W. Qian, V.P. Dravid, J.L. Schindler, C.R. Kannewurf, D.B. Studebaker, T.J. Marks, and R. Feenstra, "In-situ Growth and Doping of Oxycarbonate SrCuO₂(CO₃) Epitaxial Thin Films," Physica C, Vol. 303 pp. 11-20, 1998.

B. Wessels, B.H. Hoerman, G.M. Ford, and L.D. Kaufman, "Dielectric Properties of Epitaxial BaTiO₃ Thin Films," Appl. Physics Lett., Vol. 73, pp. 2248-2250, 1998.

B. Wessels, M. A. Reshchikov and G.-C. Yi, "Behavior of 2.8 and 3.2 eV Photoluminescence Bands in Mg Doped GaN at Different Temperatures and Excitation Densities," Phys. Rev. B, Vol. 59, 1999.

H. P.Yuen and A. M. Kim, "Classical noise-based cryptography similar to two-state quantum

cryptography," Physics Lett, Vol. 241, pp. 135-138, 1998.

S.T.Ho, H. Cao and R.P.H. Chang, "Random Lasers," Gordon Research Conference, New London New Hampshire, July 25-31, 1999.

S.T.Ho, H. Cao and R.P.H. Chang, "Random Random Laser Action in Disordered Media," Physics of Quantum Electronics Snowbird, Utah, Jan. 3-6, 1999.

S.T.Ho, H. Cao and R.P.H. Chang, "Random Laser Action in a Disordered Medium," OSA Annual Meeting, Baltimore, Maryland, Oct. 4-9, 1998.

S.T.Ho, H. Cao and R.P.H. Chang, "Random Laser Action in Disordered Media." Materials Research Society 1998 Fall Meeting, Boston, MA, Dec. 1998.

S.T.Ho, H. Cao and R.P.H. Chang, "Far-field Characteristics of Random Lasers in Polycrystalline Films," OSA Annual Meeting, , Baltimore, Maryland, Oct. 4-9, 1998.

P. Kumar, G. D. Bartolini, D. K. Serkland, and W. L. Kath, " Parametric-Amplification based Storage Buffers and Regenerators for Tb/s Packet-Switched Networks," in

Proceedings of the 4^th International Conference on Fiber Optics and Photonics (PHOTONICS-98), New Delhi, India, A. Sharma and A. Ghatak, eds, pp. 527-533, December 1998.

P. Kumar, D. Levandovsky and M. Vasilyev, "Bright sub-Poissonian light from a GAWBS-compensated nonlinear-fiber Sagnac interferometer,"Quantum Electronics and Laser Science Conference (QELS'99) Baltimore, MD, May 23--28, 1999, paper QTuG14.

P. Kumar and with D. K. Serkland, "Tunable Pulsed Fiber-Optic Parametric Oscillator," 1999 Optical Fiber Communications Conference (OFC'99), San Diego, CA, February 21--26, 1999, paper TuB4.

P. Kumar and G. Kanter, "A push-pull nonlinear Sagnac interferometer based on internally-seeded cascaded nonlinearity,'' 1998 Optical Society of America Annual Meeting, Baltimore, MD, October 1998, paper ThB6.

P. Kumar, M. Vasilyev, S.-K. Choi, and G. M. D'Ariano, "Measurement of the joint photon-number distribution of a two-mode quantum state by means of optical homodyne tomography," 1998 Optical Society of America Annual Meeting, Baltimore, MD, October 1998, August 1998, paper ThZZ3.

B. Wessels, "Epitaxial Ferroelectric Oxides for Electro-Optic and Non-Linear Optical Application," Materials Research Soc. Proc., Vol 495, 1998.

B. Wessels, M. A. Reshchikov and G.-C. Yi, "Defect Luminescence in Heavily Mg Doped GaN," Materials Research Soc. Proc, Vol. 537, 1999.

B. Wessels, B.M. Nichols, J.A. Belot and T.J. Marks, "Epitaxial KNbO₃ and its Nonlinear Optical Properties," Materials Research Soc. Proc, Vol. 541, 1999.

B. Wessels, S. Chattopadhyay and A. Teren, "Strain in Epitaxial BaTiO₃ Thin Films Prepared by MOCVD", Materials Research Soc. Proc, Vol. 541, 1999.

B. Wessels, G.M. Ford and A. Teren, "Luminescent Properties of Er-doped BaTiO₃ Thin Films for Optical Waveguides," Proc SPIE, 1999.

P. Kumar, "Spatially broadband parametric amplification: quantum-noise correlations and noiseless optical amplification of images,'' 8th International Laser Physics Workshop (LPHYS'99), Budapest, Hungary, July 2--6, 1999.

P. Kumar, "Optical Homodyne Tomography of the Twin-Beam State," Department of Physics, Univeristy of Rome "La Sapienza", Italy, June 25, 1999.

P. Kumar, "Spatially broadband parametric amplification: quantum-noise correlations and noiseless amplification of images,'' European Laboratory for Nonlinear Spectroscopy (LENS), University of Florence Italy, June 17, 1999.

P. Kumar, "Optical Homodyne Tomography of the Twin-Beam State,'' European Laboratory for Nonlinear Spectroscopy (LENS), University of Florence, Italy, June 17, 1999.

P. Kumar, "Spatially broadband parametric amplification: quantum-noise correlations and noiseless amplification of images," Physics Department, University of Milan, Italy, June 14, 1999.

P. Kumar, "CRYPTOLOGY: From Quantum to Classical, From Novel to Well-Known,'' Laboratory for Physical Sciences, College Park, MD, June 9, 1999.

P. Kumar, "Quantum optics with short pulses: some recent experimental and theoretical developments" 6^th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'99), Centro Universitario di Monte Sant'Angelo, Universita ``Federico II,'' Napoli, Italy, 24--29 May 1999.

P. Kumar, "Spatially broadband parametric amplification: quantum-noise correlations and noiseless amplification of images,'' Workshop on Fundamental Issues in Image Formation, Detection, and Processing Albuquerque, NM, February 6-7, 1999.

P. Kumar, "Parametric-Amplification based Storage Buffers and Regenerators for Tb/s Packet-Switched Networks," 4^th International Conference on Fiber Optics and Photonics (PHOTONICS-98), New Delhi, India, December 1998.

P. Kumar, " Squeezed-light generation by means of the traveling-wave interaction using picosecond pulses,'' 1998 Optical Society of America Annual Meeting, Baltimore, MD, October 1998, paper ThZZ1.

P. Kumar, "Some Recent Classical and Quantum Applications of Nonlinear Fiber-optics," Stanford University, Stanford, CA, February 22, 1999.

P. Kumar, ‘Have We Exploited Glass Fully Yet?" Tech Corporate Partners Annual Technology Review, McCormick School of Engineering & Applied Science, Northwestern University, March 23, 1999.

B. Wessels, "Engineering on an Atomic Scale", Walter P. Murphy Professorship Lectures, Chicago, IL, November 4, '98.

B. Wessels, "Defect Luminescence in Heavily Mg-Doped GaN," Materials Research Soc. Fall Meeting, Boston, MA, December 98.

B. Wessels, "Epitaxial KNbO₃ and its Non-Linear Optical Properties," Materials Research Soc. Fall Meeting, Boston, MA, December '98.

B. Wessels, "Residual Strain in Heteroepitaxial BaTiO₃ Thin Films," Materials Research Soc. Fall Meeting, Boston, MA, December '98.

B. Wessels, "Photoluminescence Spectroscopy of the 2.9 eV Band in Undoped GaN Epitaxial Layers," American Physics Soc., Atlanta, GA, March 24, 1999.

B. Wessels, "The Phase Transition in BaTiO₃ Ferroelectric Thin Films," American Physics Soc., Atlanta, GA, March 24, 1999.

B. Wessels, "Kinetics of Island Coarsening for Highly Strained Semiconductor Layers," American Physics Soc., Atlanta, GA, March 25, 1999.

B. Wessels, "Heteroepitaxy of Ferroelectric Thin Films", American Physics Soc., Atlanta, GA, March 26, 1999.

B. Wessels, "MOCVD Synthesis of Thin Film Superconductors," STCS Workshop, Universiity of Illinois, Chicago IL, June 28, 1999.

B. Wessels, "The Effect of Thickness on the Dielectric Properties of Thin Epitaxial films of BaTiO₃," 41^st TMS Electronic Materials Conference, Santa Barbara, CA, July 1999.

B. Wessels, "Investigation of the Formation of the 2.8 eV PL Band in P-Type GaN," 41^st TMS Electronic Materials Conference, Santa Barbara, CA, July '99.

H. P. Yuen, "Cryptography, from quantum to classical, from novel to well known," Laboratory for Physical Sciences, University of Maryland, College park, MD, June 10, 1999.

S. T. Ho, session chair, IEEE Lasers and Electro-Optics Society 1997 Annual Meeting, San Francisco, CA, 1999.

P. Kumar, session chair, 8th International Laser Physics Workshop (LPHYS'99): Modern Trends in Laser Physics, Budapest, Hungary, July 2-6, 1999.

P. Kumar, session chair, 4th International Conference on Fiber Optics and Photonics (Photonics-98), New Delhi, India, December 14-18, 1998.

P. Kumar, session chair, Optical Society of America Annual Meeting, Baltimore, MD, October 4-9, 1998.

S. T. Ho, Photonic, Sen and J.P. Zhang. U.S. Patent 5878070, Wire Microcavity Light Emitting Devices, March 2, 1999.

S. T. Ho , U.S. Patent Number 5790583, Photonic Well Microcavity Light Emitting Devices, Sept 1998.

S. T. Ho, D. Chu, J.P. Zhang and S. Wu, U.S. Patent Number 5825799, Microcavity Semiconductor Laser, October 1998.