Chemimage Corporation

Chemimage Technologies LLC

George Ventouris

Lei Shi

Thomas Voigt

Zili Li

Michael G Fuhrman

A non-mechanical liquid crystal tunable filter (LCTF) assembly capable of switching between a multi-conjugate filter mode and a conformal filter mode is described. The non-mechanical LCTF architecture can include a plurality of LCTF components that each comprises a first optical filter comprising a first optical axis, a second optical filter comprising a second optical axis, wherein the second optical axis is rotated 90&#xb0; relative to the first optical axis, and a first twisted nematic cell positioned between the first optical filter and the second optical filter, the first twisted nematic cell configured to polarize received light by 90&#xb0; when a voltage is not applied and not polarize the received light when the voltage is applied. The non-mechanical LCTF assembly is configured to switch between a conformal filter mode and a multi-conjugate filter mode based on whether the voltage is applied to each of the plurality of LCTF components.

Non-mechanical multi-mode MCF/CF

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

Short-wavelength infrared (SWIR) multi-conjugate liquid crystal tunable filter

Short wave infrared multi-conjugate liquid crystal tunable filter

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Valley City, OH, United States of America

George Ventouris