Multi-spectral planar imaging using a tuneable Lyot-Ehman filter

Abstract

Abstract The paper provides results of the assessment of a multi-spectral 2D imaging by using a tuneable band-pass optical filter. The filter is based on the Lyot-Ehman physical principles and uses liquid crystal cells as polarization rotators. The spectral properties of the filter are tested by imaging fluorescence of a Rhodamine dye solution. Full width at half maximum of the band of the filter was found to be 9-10 nm in the tested range of 520-620 nm. The filter is applied for 2D imaging of local spontaneous Raman scattering in a laminar premixed Bunsen flame. It is shown that the local intensity of Stokes and anti-Stokes components of rovibrational transitions during the light scattering by nitrogen molecules can be captured by using this filter. It is also concluded that the filter can be used for 2D imaging of local fluorescence in gases or liquids.