Mid-Wave Ir Liquid Crystal Tunable Retarder For Spectrapolarimetric Imaging

In this paper, the development of a compact, electronically tunable liquid crystal tunable retarder (LCTR) for manipulation of polarization is presented. A LCTR with one-inch aperture diameter has been designed and fabricated for operation over mid-wave IR (MWIR) spectral band. Using this device, quarter and half-wave retardation have been demonstrated at several prominent laser wavelengths in the MWIR spectral region. Up to 74% efficiency has been demonstrated at 2.4 mum wavelength. Highly efficient retarders are now being developed using perfluorinated liquid crystal mixtures. An LCTR Is anticipated to guide the development of a compact, wideband, and electronically tunable spectrapolarimetric imager.