The design of resonant-cavity-enhanced photodetectors for a high bandwidth-efficiency product

A high-bandwidth-efficiency (BWE) product is a basic photodetector requirement for use in ultrawide-band optical interconnecting and communication systems. An InP-InGaAs resonant-cavity enhanced (RCE) vertically illuminated p-i-n photodiode with a silicon dioxide antireflection-coating layer is simulated. The analysis reveals that not only does the antireflection-coating layer have an effect on the quantum efficiency but it also has an indirect effect on the bandwidth. For a simulated device with an antireflection-coating layer varying from 0 to 0.094 µm, the BWE product varies from 25 to 275 GHz. These values of the BWE product correspond to an active layer thickness of between 0.095 and 1.16 µm. Based on this, a simple design approach is suggested so as to achieve high-BWE products for RCE transit-time limited photodetectors.