In/sub 0.53/Ga/sub 0.47/As/In/sub 0.52/Al/sub 0.48/As separate absorption, charge, and multiplication layer long wavelength avalanche photodiode

The authors demonstrate the use of In/sub 0.52/Al/sub 0.48/As as the gain material in a separate absorption, charge, and multiplication layer avalanche photodiode (APD) with sensitivity to 0.9-1.7 /spl mu/m wavelength light. A hole to electron ionisation rate ratio of k=0.23 is observed, representing a significant improvement over the 1/k=0.4 characteristic of InP/In/sub 0.53/Ga/sub 0.47/As avalanche photodiodes. Primary dark currents of /spl sim/10 nA and gains approaching 100 for 100 /spl mu/m diameter mesa devices are observed. A 6 dB sensitivity advantage is measured for an APD receiver over an In/sub 0.53/Ga/sub 0.47/As p-i-n detector receiver at a wavelength of 1.55 /spl mu/m, a bit rate of 1.5 Gbit/s, and 10/sup -9/ bit error rate.