Upmost efficiency, few-micron-sized midwave infrared HgCdTe photodetectors

A few-micron thick structure that shows nearly 100% resonant polarized absorptance at a predefined midinfrared wavelength is designed and simulated. Like resonant-cavity enhanced photodetector structure, it contains a thin absorber enclosed in a dielectric cavity but surrogates the mirrors by two grating-on-layer structures. Fair manufacturing tolerance while maintaining high peak efficiency is proved. Electromagnetic fields amplitudes and Poynting vector over the cavity-absorber area are visualized and topology of electromagnetic power flow for two linear polarizations is discussed.