7 May 1996 Binary-optic reflection grating for an imaging spectrometer
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A single optical element capable of both wavelength dispersion and imaging would be useful for implementing compact imaging spectrometers. We have fabricated a hybrid refractive/diffractive element that accomplishes these goals. The element is a plano-convex glass lens with a reflective diffractive surface fabricated on the planar side. The diffractive surface combines a blazed grating and several forms of aberration correction. The surface relief profile was fabricated in poly-methyl methacrylate (PMMA) by direct-write electron beam (E-beam) lithography followed by a single development step. The 8.2 mm X 8.2 mm exposure pattern was corrected for both the nonlinear dose response of the PMMA and the E-beam proximity effect. Surface characterization by atomic force microscopy revealed that the grating blaze profile was linear, although the grating was overetched. Optical characterization included diffraction efficiency measurements, knife-edge spot size measurements, and CCD spot irradiance profiles at multiple wavelengths and field positions. The measured spot and field sizes translate to a resolution of 65 wavelength channels in the 400 to 700 nm band of interest and 128 spots along the imaging direction for a 10 mm entrance slit.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Daniel W. Wilson, Daniel W. Wilson, Paul D. Maker, Paul D. Maker, Richard E. Muller, Richard E. Muller, } "Binary-optic reflection grating for an imaging spectrometer", Proc. SPIE 2689, Diffractive and Holographic Optics Technology III, (7 May 1996); doi: 10.1117/12.239629; https://doi.org/10.1117/12.239629


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