Polarizing wavelength separator

Abstract

Abstract A polarizing wavelength separating optical element, PWS, in the form of a flat panel causes each of a plurality of polychromatic optical beams from a source, entering at one surface and transmitted to the other surface, to be converted with high conversion efficiency into beams circularly polarized, spectrally separated and spatially separated. The input optical beams are identical and in the form of a linear periodic array illuminating the PWS element. Output circularly polarized beams are spatially separated by a variable distance and have separated wavelengths that can be in any order: ascending, descending or random. The PWS is made of a periodic array of cells whose period is identical to that of the optical source. Each cell comprises a plurality of subcells. One subcell functions as a broadband reflector, while each of the remaining subcells functions as a polarizing wavelength selective reflector. The number of the latter subcells depends on the number of wavelengths or wavelength bands to be separated. Each subcell in turn comprises a plurality of layers that are bonded together at their surfaces which are oriented at a 45° angle relative to the horizontal surfaces of the PWS panel. In each subcell, the plurality of layers comprise two cholesteric liquid crystal, CLC, films which reflect at a selected wavelength, at least one phase shifting layer (optical retarder), and an appropriate number of clear substrates which provide mechanical supports. The thicknesses of the supporting substrates are designed to cause the optical beams transmitted through the PWS to be spatially separated by appropriate distances. Direct view displays and projection displays are simplified.

Inventors

• 👤 Sadeg M. Faris

Bibliographic Details