Sensitivity of High-Speed Lightwave System Receivers Using InAlAs Avalanche Photodiodes

Calculations based on a rigorous analytical model are carried out to compare the sensitivity of optical receivers that use InP and In
_0.52
Al
_0.48
As avalanche photodiodes (APDs). The model includes the effects of intersymbol interference, tunneling current, avalanche noise and its correlation with the stochastic avalanche duration, dead space, and transimpedance amplifier noise. For a 10-Gb/s system with a bit-error rate of 10
^-12
, the optimum receiver sensitivity predicted for In
_0.52
Al
_0.48
As and InP APDs is -28.6 and -28.1 dBm, respectively, corresponding to a reduction of 11% in optical signal power for receivers using In
_0.52
Al
_0.48
As APDs. Thus, considering overall receiver sensitivity, the improvement offered by In
_0.52
Al
_0.48
As APDs over InP is modest.