A polarization insensitive narrowband tunable filter utilizes an active liquid crystal cell to change the index of refraction and tuning of a waveguide resonant filter employing a nanostructured waveguide grating and polarization beam splitters to independently channel and convert S- and P-polarization...http://www.google.es/patents/US7009680?utm_source=gb-gplus-sharePatente US7009680 - Narrow band tunable filter with integrated detector
Narrow band tunable filter with integrated detector
