16 February 2015 Beam uniformity analysis of infrared laser illuminators
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Uniform near-infrared (NIR) and short-wave infrared (SWIR) illuminators are desired in low ambient light detection, recognition, and identification of military applications. Factors that contribute to laser illumination image degradation are high frequency, coherent laser speckle and low frequency nonuniformities created by the laser or external laser cavity optics. Laser speckle analysis and beam uniformity improvements have been independently studied by numerous authors, but analysis to separate these two effects from a single measurement technique has not been published. In this study, profiles of compact, diode laser NIR and SWIR illuminators were measured and evaluated. Digital 12-bit images were recorded with a flat-field calibrated InGaAs camera with measurements at F/1.4 and F/16. Separating beam uniformity components from laser speckle was approximated by filtering the original image. The goal of this paper is to identify and quantify the beam quality variation of illumination prototypes, draw awareness to its impact on range performance modeling, and develop measurement techniques and methodologies for military, industry, and vendors of active sources.
© 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)
Toomas H. Allik, Toomas H. Allik, Roberta E. Dixon, Roberta E. Dixon, R. Patrick Proffitt, R. Patrick Proffitt, Susan Fung, Susan Fung, Len Ramboyong, Len Ramboyong, Thomas J. Soyka, Thomas J. Soyka, } "Beam uniformity analysis of infrared laser illuminators," Optical Engineering 54(2), 026103 (16 February 2015). https://doi.org/10.1117/1.OE.54.2.026103 . Submission:

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