James R. Leger
Professor

B.S., 1974, Applied Physics, California Institute of Technology
Ph.D., 1980, Electrical Engineering, University of California, San Diego

Telephone: (612) 625-0838
Office Hours

E-mail: leger@ece.umn.edu
Web Page: http://www.ece.umn.edu/users/leger/

My research group is applying newly developed techniques in Fourier optics and holography to a variety of modern electrooptic devices. This integration of Fourier optics and electrooptics has led to many new applications ranging from optical pattern recognition to novel laser systems. Much of this work is interdisciplinary, drawing on various aspects of modern optics, signal processing, and device physics.

Microoptics is used in conjunction with a variety of electrooptic devices to perform novel functions. For example, microlens arrays are being used to establish coherence across arrays of diode lasers. Special laser cavities exploit the unusual diffractive properties of arrays to control the laser far-field pattern. An emphasis is placed on employing microfabrication techniques to construct compact and integrated devices.

Optical elements for performing geometrical transformations are being studied for a variety of applications. These include efficient pumping of solid-state and fiber lasers as well as providing power and clock signals to optical logic devices.

A final area of interest is robotics and automatic inspection. Areas of previous research include metrology and depth sensing, pattern recognition, and information compression techniques.


Selected Publications

"External Methods of Phase Locking and Coherent Beam Addition", Chapter 9 of the book Surface Emitting Diode Lasers and Arrays, G. Evans and J. Hamme, ed., Academic Press, New York, 1991.

"Lateral Mode Control of an AlGaAs Laser Array in a Talbot Cavity", Appl. Phys. Lett. 55, 334-336, 1989.

"Coherent laser addition using binary phase gratings", with G. J. Swanson and W. B. Veldkamp, Appl. Optics 26, 4391-4399, 1987.

"Real-time Depth Measurement and Display Using Fresnel Diffraction and White-light Processing", with M. A. Snyder, Appl. Opt. 23, pp. 1655-1670 1984.

"Signal Processing Using Hybrid Systems", with S. H. Lee, Chapter 4 of the book Applications of Optical Fourier Transforms, H. Stark, ed., Academic Press, New York (1982).

"Image Classification by an Optical Implementation of the Fukunaga-Koontz Transform", with S. H. Lee, JOSA 72, 556-564 (1982).