23 September 1994 Comparison of a refractive and diffractive lenslet array for a Hartmann wavefront sensor
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Abstract
A high speed Hartmann wavefront sensor was designed and built for measuring refractive index variations in supersonic air flows. The device contained a lenslet array which formed an array of spots on the focal plane of a high speed camera. Spot motion at the focal plane is directly related to fluctuation of wavefront tilt in the corresponding subaperture. Both refractive and diffractive (binary optic) lenslet arrays were fabricated for the Hartmann sensor. The long focal length needed to meet resolution requirements placed tight tolerances on the wedge error in the refractive lenslets and the cement interface mounting the lenslets to the substrate lens. In spite of the use of state-of-the-art interferometric alignment techniques for assembling the refractive lenslet array, the diffractive lenslet array demonstrated superior alignment and performance. In this application binary optics demonstrated significant advantages over conventional optics. In addition to performance issues, binary optics allows reduced weight and reduced number of elements. For airborne and space applications these advantages translate into significant cost savings.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Daniel M. Brown, Daniel M. Brown, } "Comparison of a refractive and diffractive lenslet array for a Hartmann wavefront sensor", Proc. SPIE 2267, Advanced Microdevices and Space Science Sensors, (23 September 1994); doi: 10.1117/12.187465; https://doi.org/10.1117/12.187465
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