Tuned Fabry-Perot interferometer

The way for designing and analysis of the tuned Fabry-Perot Interferometer (FPI) for monochromatic wave filtering has been established and presented. The filter is filled with liquid crystal for achieving the tuneable optical axis orientation. The meaning of the refractive index dispersion on the designing and spectral characteristics of the tuned FPI has been explained in detail. The phase of reflection for the electromagnetic waves in the mirroring layers of the filter has been experimentally determined. It allows one to obtain real effective optical thickness of the filter and successfully applied 4x4-matrix method for transmission calculations. The conditions for lc substance parameters to design the FPI filter have been verified.