Theory of grating-coupler-assisted infrared spectroscopy of lower-dimensional electron systems: Local optics of anisotropic multilayer systems with grating

摘要

A new matrix method is developed, based on both the transfer-matrix technique and the modal-expansion method, for calculating the optical properties of multilayer systems of anisotropic media with grating coupler. Using this theory it is possible to calculate the transmission and reflection coefficient, the electromagnetic field distributions, and the dispersion relations of virtual modes. It is shown that the obtained results are identical with that using the scattering-matrix technique. Detailed numerical results are presented for GaAs-Ga_(1-x)Al_xAs heterostructures with a silver grating on top of the sample. Special attention is directed to the effects of both the types of Wood's anomalies on the optical spectra.