In0.53Ga0.47As/In0.52Al0.48As separate absorption, charge, and multiplication layer long wavelength avalanche photodiode

The authors demonstrate the use of In0.52Al0.48As as the gain material in a separate absorption, charge, and multiplication layer avalanche photodiode (APD) with sensitivity to 0.9-1.7 mu m wavelength light. A hole to electro n ionisation rate ratio of k = 0.23 is observed, representing a significant improvement over the 1/k = 0.4 characteristic of InP/In0.53Ga0.47As avalan che photodiodes. Primary dark currents of similar to 10 nA and gains approa ching 100 for 100 mu m diameter mesa devices are observed. A 6dB sensitivit y advantage is measured for an APD receiver over an In0.53Ga0.47As pin dete ctor receiver at a wavelength of 1.55 mu m, a bit rate of 1.5Gbit/s, and 10 (-9) bit error rate.