Solid State Research.

Abstract

LIST OF ILLUSTRATIONS LIST OF TABLES SOLID STATE DEVICE RESEARCHLow-loss single-mode GaInAsP optical waveguide branches and bends have been fabricated utilizing a buried-heterostructure geometry to achieve tight optical confinement. Branching losses as low as 0.4 dB have been obtained at 1.3 Am for branch angles of 10.The linearity of InP optoelectronic switches under constant semiconductor laser illumination is charac-* terized by measurement of the second-and third-order intermodulation outputs. Correlation between the devices' I-V curve and intermodulation levels is obtained for variations in laser power, RF input -, frequency, and optical illumination symmetry.GaInAsP diode lasers with a proton-isolated modulator have been operated with full on /off modulation at rates of 3 GHz. Both the gain and loss are actively varied in the modulator in order to Q-switch the laser.The first high-speed semi-insulating InGaAs optoelectronic switches have been fabricated and evaluated at wavelengths up to 1.24 Am. They exhibit on-state resistance as low as 300 fl and response times with FWHM equal to 40 ps. Material characteristics and performance of these photoconductive devices have been investigated.Near-bandwidth-limited pulses of 6-ps duration lasing at X = 1.2 Am have been obtained from 4-to 8-Mm-thick LPE HgCdTe layers which have been pumped longitudinally by a Nd:YAG laser. Tuning from X = 1.82 to 2.0 pm via the Burstein-Moss shift has been accomplished on a single epilayer by varying the loss in the external cavity. QUANTUM ELECTRONICSA pulsed, laser-pumped Ti:A1 2 0 3 laser has been operated with 50-percent quantum efficiency and has been tuned over a 687-to 821-nm wavelength range. Quasi-CW, room-temperature operation also has been observed. *,Optical gain from room-temperature V:KMgF 3 has been measured by a pump-probe technique. The observed cross section indicates the possible existence of excited-state absorption.Tunable CW mode-locked operation has been demonstrated from 1.65 to 2.01 pm for a Co: MgF 2 laser. and 1.61 to 1.73 Am for a Ni:MgF 2 laser. Variations in pulse width as a function of wavelength have been *observed, and pulses as short as 36 ps for Co:MgF 2 and 23 ps for Ni:MgF 2 have been obtained.The localized UV laser photopolymerization of surface-adsorbed methyl methacrylate has been used to deposit poly (methyl methacrylate) films for direct patterning of wet and dry chemical etching processes. With this negative resist process, submicrometer linewidths have been demonstrated both in polymer deposition and in pattern transfer into Si and SiO 2 .Nitrocellulose, which functions as a self-developing photoresist, has been patterned using pulsed excimer laser radiation. The resolution of the resist has been found to be less than 0.3 m. MATERIALS RESEARCHDevelopment of the graphite-strip-heater technique for zone-melting recrystallization of Si films on Si0 2 -coated Si substrates has been continued. Wafer flatness has been improved to a level approaching that required for VLSI application...