A review is presented of the properties of interdigitated metal-semiconductor-metal (MSM) Schottky barrier photodetectors based on the InGaAs-InP material system, and the performance achieved by experimental devices is discussed. The experimental work concentrates on the barrier-enhanced lattice-matched InAlAs-InGaAs device grown by low pressure organometallic chemical vapor deposition (OMCVD), which has to date yielded detectors with the highest performance characteristics. Current research on their integration with FETs to form monolithic receivers and with waveguides for on-chip optical signal processing is also included. >

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InGaAs metal-semiconductor-metal photodetectors for long wavelength optical communications

We compare different designs for very high-speed (millimeter-wave) long-wavelength photodetectors, different materials for such detectors, and different ways of characterizing the speed of these devices. Experimental results are given, showing high-speed response with bandwidths beyond 50 GHz, impulse responses less than 10 ps, and detection sensitivities to 0.1 fJ in packaged devices. Discussed is the inherent bandwidth-efficiency limit in conventional p-i-n detectors, which is then compared to theoretical and experimental results for waveguide-geometry detectors.

Ultrawide-band long-wavelength p-i-n photodetectors

For high-bit-rate long-haul fiber optic communications, the avalanche photodiode (APD) is frequently the photodetector of choice owing to its internal gain, which provides a sensitivity margin relative to PIN photodiodes. APDs can achieve 5-10-dB better sensitivity than PINs, provided that the multiplication noise is low and the gain-bandwidth product is sufficiently high. In the past decade, the performance of APDs for optical fiber communication systems has improved as a result of improvements in materials and the development of advanced device structures. This paper presents a brief review of APD fundamentals and describes some of the significant advances

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Recent Advances in Telecommunications Avalanche Photodiodes

This paper will review recent advances in linear- and Geiger mode avalanche photodiodes (APDs). The focus for linear-mode devices will be materials and structural modifications to the conventional InP/InGaAs APD that have enabled reduced excess noise and enhanced gain-bandwidth products. The discussion of Geiger mode APDs will cover the basic operation and principal performance parameters with emphasis on techniques to reduce afterpulsing.

Recent advances in avalanche photodiodes

Until the early 2000's, the avalanche photodiode (APD) was widely deployed in high-performance optical receivers that operated up to 10 Gb/s. In subsequent years, the use of APDs for high-capacity systems declined as a result of their limited gain bandwidth, the transition to coherent detection, and the development of high-efficiency modulation techniques. Recently, the rapid growth of optical-fiber communications systems that utilize baud rates up to 25 Gb/s represented by a 100-Gb/s Ethernet has led to a resurgence of research on APDs and the development of low-noise APDs with enhanced gain bandwidth. This paper presents a brief review of APD fundamentals and describes some of the recent advances.

Recent Advances in Avalanche Photodiodes

The absorption coefficient of p + -, p - -and n - -doped Ga 0.47 In 0.53 As layers, grown lattice-matched to InP, has been calculated over the wavelength range 1.0-1.7 μm from transmission and reflection measurements.

A.J. Moseley

Papers

Measurement of absorption coefficients of Ga 0.47 In 0.53 As over the wavelength range 1.0-1.7 μm