Abstract

To construct an electronically controllable phased array system in the millimeter-wave region, one needs switches and phase shifters which are operable at speeds of about one nanosecond with a time precision of several picoseconds¹. Such a speed requirement is beyond the capability of current techniques. A class of devices in which the propagation parameters of millimeter-wave signals are controlled by optically induced electron-hole plasmas in semiconductor waveguides appears to be one method of achieving such speed and precision. A complete understanding of the physics of the interaction of millimeter-waves with an electron-hole plasma is essential for the design of such devices. An outstanding problem has been the measurement of the transient response of the millimeter-wave system after illumination by low-repetition-rate, variable energy pulses. In this paper, we report a dynamic bridge technique which has the capability to measure simultaneously the relative phase and loss response of the millimeter-wave system to illumination by frequency doubled single pulses from a mode-locked Nd:YAG laser with a potential time resolution in the picosecond range.

© 1984 Optical Society of America