Noise performance of an InP/InGaAs superlattice avalanche photodiode

The noise performance of an InP/InGaAs Superlattice Avalanche Photodiode (SL-APD) has been studied theoretically to examine its suitability as a detector in optical receiver units. The results indicate that the device which has a very large gain-bandwidth product (450 GHz) provides a high receiver sensitivity compared to conventional APD. The device also exhibits a very low value of excess noise factor which results in a high value of signal-to-noise ratio. The SL-APD is expected to find useful applications as a high sensitivity photodetector in long-haul fibre optic communication systems. For a digital system, the device exhibits a very low value of bit-error rate (BER) even at moderate gain.