Novel resonant cavity-enhanced absorber structures for high-efficiency midinfrared photodetector application

摘要

A new dielectric Fabry-Perot cavity is considered for enhanced optical absorption in a thin semiconductor layer embedded within the resonant cavity. In this design, the front (furthest from the illuminated side) mirror is a grating structure with nearly perfect retroreflection. Proof of concept, including semianalytical calculation, and computer-aided design and simulation is performed for application in a midinfrared wavelength band based on a HgCdTe absorbing layer. The results indicate that this new type of cavity meets the combined challenges of significantly increasing the absorption efficiency and reducing the overall complexity and size of the entire device, in comparison to a conventional resonant cavity, in which both mirrors are formed from quarter-wavelength multilayer stacks.