Ellipsometry of a one-dimensional photonic crystal with dielectric and conductive defects

Background. Periodic layered systems have recently attracted researchers and engineers due to their possible wide applications in nanoelectronics. In such systems, in addition to their direct use as a periodic structure, various defects can be studied. Against the background of an ideal periodic structure, reflection from a structure with a defect allows one to obtain important information about the defect itself. Of particular interest is the use of circularly polarized light for these purposes. Aim. The paper presents the results of calculations of the angular spectra of ellipsometric parameters from a periodic structure with a defect. The latter uses a dielectric layer and a layer with finite conductivity. Methods. Spatial. The work uses the ellipsometric method for analyzing the optical properties of material media. Using the method of characteristic matrices, the ellipsometric parameters of circularly polarized light reflected from the layered system are calculated. Results. The work notes the non-equivalence of the calculation results for different locations of the defect - the ellipsometric parameters of the reflected light significantly depend on where the defect is located inside the structure. This effect can be used to determine this location against the background of reflection from an ideal periodic structure. In addition, it has been shown that dielectric and conductive defects lead to significantly different angular spectra of ellipsometric parameters, which can also serve as a certain marker of the defect itself. Conclusion. The use of circularly polarized radiation to diagnose periodic media with defects makes it possible to obtain important information about defects against the background of an ideal periodic structure.