Reduction of dark current in photodiodes by the use of a resonant cavity

The advantages of using a resonant cavity enhancement scheme to decrease the dark current of heterojunction photodiodes are considered. It is shown that the employment of very thin absorption layers, allowed by this scheme provides a significant reduction of the generation component of the dark current. Experimental results for InGaAs-InAlAs PIN photodiodes suggest that the tunnelling component of the dark current can be also suppressed in resonant cavity enhanced photodetectors.