Tunable snapshot imaging spectrometer

The acquisition of a multi-spectral data set in a single FPA integration time (snapshot) with no moving parts or scanning is possible with a Computed Tomographic Imaging Spectrometer (CTIS). CTIS instruments employ specially designed computer generated holograms (CGH) etched in an appropriate media for the wavelength band of interest as the dispersing element. The replacement of current etched CGHs with an electronically tunable liquid crystal Optical Phase Array (OPA) extends the capabilities of the CTIS by adding the ability to change its configuration while maintaining its basic motivation as a non-scanning imaging spectrometer with no moving parts. This tunability allows the dispersion, number of diffraction orders, and diffraction efficiency of the orders to be changed affecting the instrument's spectral resolution, data cube reconstruction quality and speed. This publication presents the results of characterizing the OPA phase vs. applied voltage profile and the feedback algorithm used to program the OPA as a CTIS disperser.