Proposition of a nearly rectangular response resonant cavity enhanced (RCE) photodetector

We propose a novel wavelength-selective photodetector with two subcavities, for obtaining a flat-top and steep-edge spectral response and a high quantum efficiency simultaneously. Simulated nearly rectangular response curves can be obtained by insert an absorption layer into the latter subcavity. We discuss the effects of key factors on the response curve of this kind of photodetector. Such devices are promising for wavelength division multiplexing (WDM) applications.