High-frequency response limitation of high performance InAlGaAs/InAlAs superlattice avalanche photodiodes

InAlGaAs-InAlAs superlattice avalanche photodiodes (SL-APDs) have been investigated for use in high bit rate optical communication systems. The high frequency response limitation of high-performance InAlGaAs/InAlAs SL-APDs is reported. For a thin avalanche layer of 0.126 /spl mu/m, a gain bandwidth product of 200 GHz and a multiplied dark current of 700 nA have been attained. These values are sustainable for use in practical systems at 20 Gbit/s.