Miniature Spectrometer Based on a Novel Optical Filter with Spectral Selectivity Distributed Along the Aperture

40389 November 18, 1996 Physical Optics Corporation Long term monitoring is needed to measure particles in the atmosphere that may contribute to environmental degradation and health problems. This project will design, fabricate, and test a new miniature spectrometer to be implemented in the DOE atmospheric measurement program. The device will be based on a novel optical filter with spectral selectivity distributed along the aperture, and will be designed in Phase I. The filter, using a novel double-wedge holographic resonator in a vernier configuration, acts as a dispersive element. The combination of a double-wedge resonator (to distribute the transmitted wavelength linearly across the aperture in a direction perpendicular to the filter's optical axis) and a vernier configuration (to ensure high effective finesse) will result in high (subangstrom) resolution across the selected bandwidth (from several to hundreds of nanometers) in the W, visible and IR range. This low-cost filter will be rugged, compact (centimeters) and light (grams), and will contain no moving parts or liquid in the resonator. Phase II will implement the filters in the design and fabrication of a miniature spectrometer that will meet DOE requirements. Anticipated Results/Potential Commercial Applications as described by the awardee: The miniature, rugged, high-resolution, low-cost spectrometer, should have value for both government agencies and private industry. Applications range from atmospheric measurement and sampling technology to biology and medicine, and to research in astrophysics and in terrestrial environments. The basic element of the proposed spectrometer, a filter with spectral selectivity distributed along the aperture, could also be useful in fiber optic telecommunications and optical computing.