Tadashi Fukuzawa

Monolithic integration of a GaAlAs injection laser with a Schottky‐gate field effect transistor

Monolithic integration of a GaAlAs laser with a GaAs Schottky‐gate field effect transistor is demonstrated. A GaAs field effect transistor with a 3‐μm gate length is formed on a double‐heterostructure laser crystal which is protected by a high‐resistivity isolation layer. Laser light intensity is modulated to realize rise and fall times of less than 0.4 ns by modulating the field effect transistor gate voltage.

InGaAsP/InP distributed‐feedback injection lasers fabricated by one‐step liquid phase epitaxy

Fabrication and lasing characteristics of InGaAsP/InP distributed‐feedback injection lasers are described. An InGaAsP active layer, a p‐InP clad layer, and an n‐InGaAsP cap layer are successively grown on an InP substrate with a 0.32‐μm periodic corrugation. The diodes emit at a wavelength of 1.1 μm up to 170 K under pulsed operation. Single longitudinal mode oscillation and a small temperature dependence of the lasing wavelength of 0.054 nm/K are obtained in these diodes.

Integration of a Laser Diode and a Twin FET

Monolithic integration of a double heterostructure laser diode and field effect transistors, all of GaAs/GaAlAs, involving only planar type fabrication processes is demonstrated. The ICs are fabricated using liquid phase epitaxy, and lift-off. The functions of normally-on type Schottky gate FETs and a Fabry-Perot type infra-red laser diode are successfully matched, to realize high speed modulation with high extinction ratio and no pattern effect. Moreover, activation of the laser by positively pulsed electric signals on gates is demonstrated utilizing an auto-bias of the ICs. The rise time of the pulsed response is about 0.4 ns, suggestive of GHz operation.