We review the family of optoelectronic devices whose performance is enhanced by placing the active device structure inside a Fabry‐Perot resonantmicrocavity. Such resonantcavity enhanced (RCE) devices benefit from the wavelength selectivity and the large increase of the resonant optical field introduced by the cavity. The increased optical field allows RCE photodetector structures to be thinner and therefore faster, while simultaneously increasing the quantum efficiency at the resonant wavelengths. Off‐resonance wavelengths are rejected by the cavity making RCE photodetectors promising for low crosstalk wavelength division multiplexing(WDM) applications. RCE optical modulators require fewer quantum wells so are capable of reduced voltage operation. The spontaneous emission spectrum of RCE light emitting diodes(LED) is drastically altered, improving the spectral purity and directivity. RCE devices are also highly suitable for integrated detectors and emitters with applications as in optical logic and in communication networks. This review attempts an encyclopedic overview of RCE photonicdevices and systems. Considerable attention is devoted to the theoretical formulation and calculation of important RCE device parameters. Materials criteria are outlined and the suitability of common heteroepitaxial systems for RCE devices is examined. Arguments for the improved bandwidth in RCE detectors are presented intuitively, and results from advanced numerical simulations confirming the simple model are provided. An overview of experimental results on discrete RCE photodiodes, phototransistors, modulators, and LEDs is given. Work aimed at integrated RCE devices,optical logic and WDM systems is also covered. We conclude by speculating what remains to be accomplished to implement a practical RCE WDM system.

Resonant cavity enhanced photonic devices

A pnn double heterostructure optoelectronic switch with dual extractor electrodes was dynamically operated as an optical memory with the resulting achievement of 20 μW holding power. This value represents a reduction in holding power of about three orders of magnitude as compared to that of conventional light‐emitting optical bistable devices. Complete operation, involving optical writing, regeneration, and high‐speed erasing of written data through a dual extractor‐electrodes configuration, was carried out with a simple driving scheme.

Double heterostructure optoelectronic switch as a dynamic memory with low-power consumption

Integrated circuits and fabrication methods incorporating both two-terminal devices such as IMPATT diodes (446) and Schottky diodes (454) and three-terminal devices such as n-channel MESFETs (480) in a monolithic integrated circuit.

Integrated circuit and method

Vertical cavity surface‐emitting lasers are integrated with GaAs/AlGaAs heterojunction phototransistors to yield optically controlled lasers. The two‐terminal device operates in several modes: As an amplifier with a large signal, external optical gain of 5, as in optical logic gate, and as an optically or electrically triggerable latch. The optical AND gate has an output on‐to‐off ratio of 10:1. Although the device has no optical feedback, latching is achieved with appropriate biasing through impact ionization. The device structure is advantageous for forming large two‐dimensional arrays for optical signal processing.

Optically controlled surface‐emitting lasers

The authors discuss digital optics, a technology for processing, transport, and storage of optical digital information. Digital optics offers both the high temporal bandwidth of fiber communications and the high connectivity and information density of optical imaging. The energy dissipation per bit of communicated information, as well as the chip area dedicated to interconnections, can be significantly lower in optics than in high-speed electronics. This motivates the introduction of parallel optical interconnections through free space in communication-intensive areas of digital information processing such as switching in telecommunications and within multiprocessors. Digital optical circuits can be constructed by cascading two-dimensional planar arrays of optical logic gates interconnected in free space. The state of the art and the trends in digital optical information processing systems for optical logic, optoelectronic interfaces, and optical free-space interconnection systems are reviewed. >

Digital optics

Two‐terminal switching action is observed in a new optoelectronic device structure. The device has a high‐impedance state without light emission and a low‐impedance state characterized by strong spontaneous emission. The transition from either state to the other may be induced by the appropriate optical or electrical input. It is clear that with the appropriate optical cavity construction the switching device will operate as a laser in the on state rather than in the spontaneous mode reported here. In principle, the device offers large digital optical gain determined by its optical sensitivity and its maximum output power.

A new double‐heterostructure optoelectronic switching device using molecular‐beam epitaxy

A three‐terminal double heterostructure optoelectronic switching (DOES) device is demonstrated. By making ohmic contact to the active region of the DOES device the switching characteristic may be controlled up to the punchthrough limit. The device emits light in the on state only and various combinations of voltage and optical input power can be used to switch the device.

Ledistor—a three‐terminal double heterostructure optoelectronic switch

The switching time of a double heterostructure optoelectronic switch is investigated using an optical input. A switch‐on time of 5–10 ps is obtained using a discrete microwave package. The fall time of 10 ns is limited almost totally by the parasitic capacitance of the package. The switching operation shows the unique ability to turn on and off with the incident optical signal.

Optically induced switching in a p-channel double heterostructure optoelectronic switch

An n‐channel double heterostructure optoelectronic switch has been demonstrated As in the case of the p‐channel device, there is a high impedance state without light emission and a low impedance state with strong spontaneous emission The states are changed by optical or electrical signals and a digital optical gain of 14 is observed The switching voltage is higher and the holding current is lower than in the p‐channel case

Experimental realization of an n-channel double heterostructure optoelectronic switch

The electrical switching speed of a new double-heterostructure optoelectronic switch (designated DOES) is measured in a relaxation oscillator circuit. A minimum value of capacitance was required to obtain oscillations. The turn-on speed was measured to be 100 ps. The turn-off speed was limited to the RC pull-up time.

R. S. Mand

Papers

A new double‐heterostructure optoelectronic switching device using molecular‐beam epitaxy

Ledistor—a three‐terminal double heterostructure optoelectronic switch

Optically induced switching in a p-channel double heterostructure optoelectronic switch

Experimental realization of an n-channel double heterostructure optoelectronic switch

Electrical switching speed of the double-heterostructure optoelectronic switch