Novel continuously tunable high spectral resolution optical filter for two-dimensional imaging

Despite the existence of a variety of optical filters for the separation of spectral components in a multicolor image, a filter that is both continuou sly wavelength tunable and capable of high spectral resolution while preser ving the spatial integrity of a two-dimensional image is not currently avai lable. We present, in this article, the introduction of a novel optical fil tering concept that permits the development of such a system. Both the conc ept and its implementation in an optical-fiber-based prototype that convert s two-dimensional images to a one-dimensional array followed by interconver sion for image reconstruction are presented. The performance of the prototy pe is analyzed using both a xenon arc lamp as a standard broadband illumina tion source as well as He-Ne and Ar lasers as sources of coherent radiation . An unoptimized throughput efficiency of approximately 30% and a bandwidth of 6 Angstrom without spectral leakage or spatial crosstalk is obtained ov er the entire investigated tuning range from 430 to 807 nm. Potential appli cations of such an optical filtration system, with wavelength tunability on the angstrom scale and potential spatial resolutions in the micrometer ran ge, using suitable optical imaging are discussed. (C) 2001 American Institu te of Physics.