P.R. Claisse

Three‐terminal operation of the double‐heterostructure optoelectronic switching laser

The double‐heterostructure optoelectronic switch is demonstrated as a three‐terminal laser. The basic laser structure employs a graded index single quantum well (GRIN SQW) and implements the third‐terminal injector as a self‐aligned implant to the inversion channel. The implant simultaneously serves as the optical confining layer. Threshold currents of 500 A/cm2 are obtained and complete control of the switching characteristic is obtained with an input current density of 0.8 A/cm2.

Demonstration of a heterostructure field‐effect laser for optoelectronic integration

A new laser structure suitable for optoelectronic integration is reported. It utilizes field effect at a heterointerface within the same structure used to build field‐effect transistors. A threshold current density of 560 A/cm2 and a differential quantum efficiency of 56% were achieved.

Demonstration of the heterostructure field‐effect transistor as an optical modulator

A new semiconductor waveguide absorption modulator is demonstrated utilizing the heterostructure field‐effect transistor structure. The modulator of 300 μm length and 10 μm width achieves an extinction ratio of 8 for a gate voltage change of 2.5 V and an absorption change greater than 2300 cm−1. The transistor transconductance is 92 ms/mm for a 1 μm device and an identical structure has been reported as an edge‐emitting laser providing an ideal combination for optoeletronic integration.

A graded index single quantum well bistable laser

The authors report the first implementation of a buried heterostructure DOES (double heterostructure optoelectronic switch), which incorporates the principles of graded-index, single-quantum-well (GRIN SQW) lasers. Continuous operation and a small signal optical bandwidth of 1.5 GHz were obtained when biased into the on-state. This is consistent with the bond pad side employed. This GRIN SQW DOES laser, fabricated in two-terminal BH form, has been shown to have properties commensurate with the growth and processing parameters employed. Although limited to two-terminal operation, performance is comparable to existing devices with similar designs.<<ETX>>

Electrical and optical switching characteristics of the single-quantum-well DOES laser

Experimental results are presented for the GaAs/AlGaAs single-quantum-well DOES (double heterostructure optoelectronic switch) laser. Switching data are reported for the three-terminal structure in which inversion channel contact is made via a self-aligned implant. They show full control of a 12-V switching characteristic with an input current of only 0.1 A/cm/sup 2/. Optical switching of one edge emitting laser was demonstrated with the optical output of another identical device. Switching energies as low as 0.15 fJ/ mu m/sup 2/ were measured using an integration time of 600 ps and a voltage of 6.7 V. The results are modeled using a new approach to describe the switching characteristics of the device. Good agreement between experimental and theoretical characteristics is shown, giving support to the new theoretical description of the device. >

Small signal and continuous wave operation of the lateral current injection heterostructure field-effect laser

The lateral current injection heterostructure field‐effect laser structure is operated both as a three‐terminal laser and a field‐effect transistor. The structure was grown by low‐temperature molecular‐beam epitaxy (580 °C) and excellent performance characteristics were obtained for both devices. The laser is shown to have both source/emitter and source/collector modes of operation. Both modes exhibited a continuous wave operation and the source/emitter mode has a −3 dB bandwidth of 4 GHz limited by heating caused by a high source resistance. The transistor had a peak transconductance of 95 mS/mm and a peak drain to source current density of 120 mA/mm for a 2μm×50 μm device.

Ultralow-threshold-current lasing in inversion channel lasers

A new regime of semiconductor laser operation was observed in quantum-well inversion channels of double heterostructure optoelectronic switches. The quantum-well active region operated with substantial excess negative charge imbalance due to the proximity of a high-density depleted donor charge sheet. Threshold current densities as low as 15 A/cm/sup 2/ in as-cleaved 400- mu m-long devices were measured, and unusual high-frequency operation under low power operation was observed. These qualities may be of great significance for optical interconnections and optoelectronic integrated circuits.<<ETX>>

Effects of drift and diffusion current flow on the high-speed performance of quantum well lasers

A new approach is described to incorporate the effects of drift and diffusion into the small signal transfer function of the quantum well semiconductor laser. The differential gain parameter is represented by the differential stimulated lifetime and is a constant, power‐independent parameter. The nonlinear gain factor is not required in the analysis with the saturation of the resonant frequency resulting instead from the effects of diffusion current flow through the active layer. The electron and photon rate equations used are interrelated by the Fermi energy as a parametric variable.

Determination of the longitudinal mode spectrum and mode suppression ratio in a quantum-well laser

The longitudinal mode spectrum and the mode suppression ratio of a quantum-well laser are derived in terms of the simulated emission lifetime of the photons in a mode. Analytic expressions are obtained from the Fermi level as a function of current and power as the limiting value of Fermi energy is approached. The model predicts the growth in spontaneous emission as the mirror reflectivity is reduced and predicts mode suppression ratios in good agreement with published values. >

Electronic/photonic inversion channel technology for optoelectronic ICs and photonic switching

A new approach to optoelectronic integration is presented in which all optical and electronic devices are derived from a single crystal growth and a single fabrication sequence. The approach uses a self-aligned inversion channel capable of functioning as an FET or bipolar transistor, a detector, a modulator or a laser in either an analog or a digital mode. Topics discussed include a three-terminal switching laser, a bipolar inversion channel field-effect transistor, a three-terminal analogue laser, an HFET detector, and an HFET optical modulator.