Optoelectronic devices for millimeter waves

Results are reported of experimental and theoretical investigations of changes occurring in the propagtion characteristics of millimeter waves in an intrinsic semiconductor waveguide in the presence of a plasma-dominated region. The electron-hole plasma is injected into the guiding medium to control the dispersion of millimeter waves through attenuation and phase-shifting of the RF signals, producing the desired mm-wave pulses. The plasma state is elicited with a laser. Null and dynamic bridge techniques and a theoretical model are described for monitoring the effects of the phase shifting and attenuation. Applications of the techniques in GaAs diode laser and frequency-doubled, mode-locked Nd:YAG laser experiments are summarized. Finally, picosecond techniques for modulating and gating mm-wave signals are outlined.