Researcher Profiles

Lok C. Lew Yan Voon

Lok C. Lew Yan Voon (llew@wpi.edu) works on band structure theory and on the optical properties of semiconductor nanostructures. Applications have included semiconductor diode lasers and quantum well infrared photodetectors (QWIPs). He has worked with the U.S. Air Force to develop laser diodes that operate at high temperatures. Using theoretical tools developed in particle physics, Prof. Lew Yan Voon is exploring schemes to tailor the electronic structure of quantum well devices to minimize the probability of thermal excitations. Thermal excitations in quantum well devices kick electrons out of the laser transition states. Thus, as the temperature increases, the gain of a quantum well laser diode plummets. Another research area includes the development of high-efficiency quantum well/dot infrared detectors that are based on intersubband transitions. In a series of papers, Prof. Lew Yan Voon and collaborators in Germany and Denmark demonstrated convincingly that n-doped QWIPs can work at normal incidence. Professor Lew Yan Voon returned to WPI in 1995 after spending eighteen months at the Max Planck Institute in Stuttgart, Germany. He has also visited Wright-Patterson AFB, Hong Kong University of Science and Technology, and Stanford University. Professor Lew Yan Voon's research has been funded by AFOSR, MRS, and the NSF. His work has also been rewarded by an Alexander von Humbold fellowship and the NSF CAREER award.

Grant McGimpsey

Grant McGimpsey (wgm@wpi.edu)is a photochemist involved with projects ranging from the development of molecular electronic logic circuits to optically controlled lithographic etching solutions to optical sensors for blood analysis. Before coming to WPI in 1989, Professor McGimpsey was a postdoctoral fellow at the National Research Council in Canada. In recent years his research interests have focused on intramolecular electron and energy transfer in large organic molecules and biomolecules using laser flash photolysis techniques. Currently he is synthesizing polychromophoric peptides and other self-assembled systems as possible alternatives to conventional silicon-based electronic devices. The NSF, ARO, Petroleum Research Corp., Polaroid Corp. and Boyer Business Group Diagnostics have supported Professor McGimpsey's research.

Richard Quimby

Richard Quimby (rsquimby@wpi.edu) conducts experiments to understand the fundamental processes occuring in optical amplifiers, such as erbium and praseodymium doped fibers, and to spectroscopically evaluate other materials doped with rare earth ions such as fluoride glasses, sulfide glasses, and transparent glass ceramics. His contributions toward understanding how to quantify radiative and nonradiative processes in these materials has led to significantly improved experimental techniques to measure absorption and emission cross sections. This widely used calibration technique allows material researchers to identify processes that contribute to an inefficient gain in optical amplifiers. His research is in part driven by desire to obtain ultra wide band amplifiers and lasers (up to 40 THz) for the telecommunication industry. Professor Quimby has received support from the U.S. Air Force, GTE, and Corning, Inc.

Alex Zozulya

Alex Zozulya (zozulya@wpi.edu) is exploring means to turn recent breakthroughs in cold-atom technology into high-precision instrumentation. By taking advantage of the short characteristic wavelength of coherent atoms (- 1 nm), scientists hope to enhance the precision of interferometric devices such as atomic clocks and gravitometers by 1000 fold. Professor ZozuIya arrived at WPI in 1998 after spending six years at JILA (Boulder, Colorado) and fourteen years at the Lebedev Physics Institute (Moscow). He is a world-renowned optical theorist, with over 100 publications in areas such as photo refraction, nonlinear optics, and cold-atom physics. Using the theory of the interaction of light with matter, Professor Zozulya is exploring ways to design atom-optics devices. He is also investigating the unusual propagation characteristics of light through "holy" fibers, and applications of the ultra-slow speed of light in cold atoms. The Army Research Office is supporting this work.