Resonant cavity photodetector with integrated spectral notch filter

A p-i-n resonant cavity enhanced photodetector for absorption at 1.55 μm has been integrated with two stacks of six pairs of ZnSe-MgF
₂
dielectric mirrors. The stacks act as a notch filter to reflect off-peak radiation. Peak external quantum efficiency over 90% was achieved at 1.52 μm, with off-peak rejection of approximately 20 dB across a 700-nm range. Design of the structure was based on simulations using the transfer matrix method.