Study On Semiconductor Far-Infrared Mirrors

In this paper, we first introduce the importance of the study on the infrared physics, the actuality of the far-infrared (FIR) detector, the challenges and the problems that need to be solved. Then we present the principles of Fourier Transform Spectroscopy and the physics image of FIR spectrum that are used in our research. We go on introducing some principles such as the Optical Transfer Matrix Method, semiconductor optical parameters, Kramers-Kronig relation, and the reflectivity and the transmission models of the semiconductor films.We have carried out an in-depth investigation on the reflectivity and phase shift of a novel semiconductor mirror, which can be applied in the FIR spectral range. By fitting FIR reflection spectra of the mature GaAs material with different doping concentrations, two empirical formulas are obtained for the doping concentration-dependent carrier relaxation time of n-GaAs and p-GaAs. We have a qualitative analysis on the ratio between the mobility from Hall experiment and the results from fitting the FIR reflectivity spectrum. The effects of structure and material parameters on the reflectivity and the phase shift of the mirror are analytically studied in detail based on the deduced formula. All the related parameters of the...