POLARIZATION-BASED TUNABLE INTERFEROMETRIC FILTER

A polarization-based tunable interferometric filter essentially consis ting of a two-beam interferometer with birefringence elements is descr ibed. The analysis of the filter is done through the concept of a geom etric phase in optics-namely, the Pancharatnam phase. The transmission characteristics of the filter can be controlled through three paramet ers: the thickness of the birefringent elements, the optical path diff erence, and the orientation angle of an analyzer placed at the interfe rometer output. It is demonstrated theoretically that, with a particul ar choice of these parameters, the chromatic dispersion of the filter is compensated in a given spectral range. Some properties of the devic e are confirmed by an experimental demonstration. (C) 1998 Optical Soc iety of America.