Study of grating performance for quantum well photodetectors

摘要

The performance of reflective grating plays a key role in quantum well infrared focal plane arrays due to the selection rules of inter-subband transition. In this paper, the reflective properties of metal grating have been studied by the finite-difference time-domain methods. Not only are the optimal grating parameters found to be different from the suggested values, but also a new choice for grating design has been found due to the exciting of surface wave. In addition, cavity modes can be formed when the dielectric thickness is finite. The grating performance is also greatly affected by the cavity modes. The presented results may have some significance for experimental design.