Analysis and comparison of n-AlxGa1−xAs/GaAs QWIPs with different device structures and optical coupling

This paper discusses optical coupling for n-GaAs/AlGaAs multiple quantum well infrared photodetectors (MQWIPs). The optical responsivity has been compared with different grating structures fabricated by reactive ion etching (RIE), device form, and incidence mode. The optical coupling efficiencies are further analyzed by the modal expansion model (MEM), including optical field distributions in different size photosensitive element and interrelated influences with scattering matrix method based on plane-wave expansion (PWE). Some extra coupling parameters have been obtained in designing and optimizing QWIPs FPA.