Short wave infrared multi-conjugate liquid crystal tunable filter

摘要: A SWIR hyperspectral imaging filter has serial stages along an optical signal path with angularly distributed birefringent retarders and polarizers. The can include active such as tunable liquid crystal elements, passive fixed retarders, and/or combinations thereof. Distinctly different periodic transmission spectra are provided by stages, each having multiple in particular some broad bandpass peaks at wide spectral spacing other have very narrow closely spaced peaks. respective least one tunably selectable band which the of coincide, whereby salutary ranges apply together, resulting a high finesse wavelength suitable for imaging. may be configured to provide faster switching speed increased angle acceptance operate rage approximately 850-1700 nm.