Translator Disclaimer
3 November 2003 Tandem-etalon tunable filter for NIR spectral imaging
Author Affiliations +
Scientific Solutions Inc. (SSI) has developed a tunable liquid crystal Fabry-Perot (LCFP) etalon system comprised of a resolving and a suppression etalon in tandem. The 30-micron resonant cavity spacing of the resolving etalon provides for high spectral resolution while the system maintains the significantly broader free spectral range of the 6-micron gap suppression etalon across the tunable region. An applied electric field alters the ordinary refractive index of nematic liquid crystal cells within each etalon cavity, thereby altering the resonant properties of the etalons, allowing for system tunability over several orders of interference. This system acts as a tunable optical filter with an operating range from 700nm to 1100nm. Testing of the LCFP etalon system with both a high resolution Czerny-Turner monochrometer and a stabilized ND:Yag laser demonstrate a FWHM of 0.67nm to 1.03nm. System transmission reaching 70% of polarized light is achieved with tunability over one free spectral range in approximately 30 milliseconds. The free spectral range of the tandem etalon system ranges from 27nm-36nm over the operating range, and allows for 40 randomly selectable spectral channels per free spectral range. This system is designed for use in spectral imaging systems, initially for the semiconductor industry, but is equally applicable to the earth remote sensing community.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
John Noto, Yan Betremieux, Robert B. Kerr, Hailiang Zhang, Michael J. Taylor, Steve Watchorn, and Michael Dorin "Tandem-etalon tunable filter for NIR spectral imaging", Proc. SPIE 5157, Optical Spectroscopic Techniques and Instrumentation for Atmospheric and Space Research V, (3 November 2003);


Imaging spectroscopy using tunable filters: a review
Proceedings of SPIE (April 04 2000)
Wavelength selection in OSIRIS
Proceedings of SPIE (March 06 2003)
Liquid crystal Fabry-Perot etalons
Proceedings of SPIE (July 08 1998)

Back to Top