InAlAs-InGaAs based avalanche photodiodes for next generation eye-safe optical receivers

This paper presents results of three research and development efforts on the subject of avalanche photodiodes with InGaAs absorbers and InAlAs multiplication layers. The first portion of the paper presents results on 256x256 arrays of InAlAs-InGaAs APDs. These spanned more than 1.5 cm x 1.5 cm, had breakdown voltage variation of less than 2.5 volts and a dark current range between 1.5 and 3.5 nA at a gain of 10. The second portion of the paper presents single photon detection results of a receiver with a 50 micron aperture avalanche photodiode biased into sub-Geiger mode and a Maxim MAX3658 transimpedance amplifier. At temperatures of 200K and average avalanche gains approaching 1000 single photon detection efficiencies greater than 5% were observed with dark count rates of less than 500 kHz. At 175 K detection rates were as high as 14%. Finally, in the third portion of this paper, performance results of a novel impact ionization engineered InGaAs-InAlAs based avalanche photodiode are presented showing excess noise values lower than any previously published InGaAs based avalanche photodiode.