Recent developments in both GaAs- and InP-based opto-electronic circuits (OEIC's) which incorporate both optoelectronic and electronic devices on the same semiconductor substrates will be discussed. Several key technologies required for optoelectronic integration and the present status of the technology are explained by reviewing some of OEIC transmitters and receivers that have been realized up to now. Possibilities of application of OEIC's and further technological challenges to enhance the advantages of OEIC's are discussed.

Recent progress in optoelectric integrated circuits (OEIC's)

The remarkable early success and current explosive growth of electronic integrated circuits have fascinated photonics researchers since 1969 with the prospect of similar success in optical integrated circuits. Alas, physical and economic factors have stymied their efforts. Two recent commercial optical integrated circuits may be the first points on a photonic Moore's law curve. The author presents his view of the progress of optical integrated circuits since S. E. Miller's proposal in the 1969 Bell Systems Technical Journal .

/pdf/optical-integrated-circuits-a-personal-perspective-1090cgozlr.pdf

Optical Integrated Circuits: A Personal Perspective

We present an analysis of Schottky barriers in n-InP made by incorporating a thin native oxide. An oxidation technique using nitric acid under illumination produces an oxide layer with uniform composition distribution within the layer. The growth rate is interpreted as being partially limited by diffusion presumably of oxygen through oxide. The Au Schottky barrier formed on a 40–80 A thick oxide layer exhibits little degradation of the ideality factor n (1.04 < n < 1.10) and an increase of the barrier height by greater than 0.3 eV, resulting in at least a 10−4 times smaller reverse leakage current density, compared with conventional Au-InP barriers. The barrier height increase is analysed by a generalised model, and is found to be produced by the existence of fixed negative charges in the oxide layer. From the present analysis, a surface state density of 6.0 × 1012 cm−2 eV−1 and an equivalent surface density of negative charges of 2.8 × 1012 cm−2 are determined independently. The origins of these, particularly of the surface states, are considered in relation to the P vacancies at the oxide-InP interface.

InP Schottky contacts with increased barrier height

A technique has been developed for cleaving the mirrors of AlGaAs lasers without cleaving the substrate. Micro‐cleaving involves cleaving a suspended heterostructure cantilever by ultrasonic vibrations. Lasers with microcleaved mirrors have threshold currents and quantum efficiencies identical to those of similar devices with conventionally cleaved mirrors.

/pdf/algaas-lasers-with-micro-cleaved-mirrors-suitable-for-58gpofmpgl.pdf

AlGaAs lasers with micro-cleaved mirrors suitable for monolithic integration

Light-induced voltage and the change in the source-to-drain channel current under optical illumination higher than the semiconductor band gap for GaAs MESFET, InP MESFET, Al/sub 0.3/Ga/sub 0.7/As/GaAs high electron mobility transistor (HEMT), and GaAs permeable base transistor (PBT) are analytically obtained. The GaAs PBT and GaAs MESFET have higher sensitivity than the InP MESFET. However, the Al/sub 0.3/Ga/sub 0.7/As/ GaAs HEMT is observed to have the highest sensitivity. Variations in the small-signal parameters, such as channel conductance, gate-to-source capacitance, and transconductance, as well as transient parameters, such as switching time and power-delay product, of GaAs MESFET with illumination are computed. The computed capacitance and transconductance are compared with the experimentally obtained values and are found to be in fair agreement. Based on these results, the design considerations for an optically controlled MESFET switch are discussed. Finally, variation in device parameter due to optical illumination and its effect on the cutoff frequencies f/sub T/ and f/sub max/ are also investigated.

/pdf/analysis-of-optically-controlled-microwave-millimeter-wave-p2a421gb4k.pdf

Analysis of Optically Controlled Microwave/Millimeter Wave Device Structures

A monolithically integrated optical repeater has been fabricated on a single‐crystal semi‐insulating GaAs substrate. The repeater consists of an optical detector, an electronic amplifier, and a double heterostructure crowding effect laser. The repeater makes use of three metal semiconductor field effect transistors, one of which is used as the optical detector. With light from an external GaAlAs laser incident on the detector, an overall optical power gain of 10 dB from both laser facets was obtained.

/pdf/a-monolithically-integrated-optical-repeater-3dzt8knhk7.pdf

A monolithically integrated optical repeater

Mutual phase locking has been achieved through series connection of a semiconductor laser and a Gunn diode oscillator. Experimental results obtained demonstrate a mutual interaction between the two oscillators which results in a short term Gunn diode oscillator stability and improved spectral purity of its output. We also observe a narrowing of laser pulses and an improvement in regularity.

/pdf/mutual-phase-locking-of-a-coupled-laser-diode-gunn-diode-2ihbcl9zg0.pdf

Mutual phase locking of a coupled laser diode‐Gunn diode pair

High repetition rate picosecond optical pulse generation is achieved by providing electrical feedback (with and without external gain) to a self‐pulsating laser diode. The feedback improves pulsation short‐term stability (<25‐kHz frequency jitter) and narrows the laser pulses (14 ps).

/pdf/variable-frequency-picosecond-optical-pulse-generation-from-qfgrmu9755.pdf

S. H. Izadpanah

Papers

A monolithically integrated optical repeater

Mutual phase locking of a coupled laser diode‐Gunn diode pair

Variable frequency picosecond optical pulse generation from laser diodes by electrical feedback