【摘 要】
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A method for beam diffraction sidelobe suppression based on the combination of volume Bragg gratings (VBGs) with different thicknesses or periods for angular filtering is proposed and performed. Simulated and experimental results show that the beam diffra
【机 构】
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CollegeofPhysics,OptoelectronicsandEnergy,SoochowUniversity,Suzhou215006,ChinaKeyLabofAdvancedOptica
【出 处】
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ChineseOpticsLetters
论文部分内容阅读
A method for beam diffraction sidelobe suppression based on the combination of volume Bragg gratings (VBGs) with different thicknesses or periods for angular filtering is proposed and performed. Simulated and experimental results show that the beam diffraction sidelobe is reduced from 12% to less than 1% with the non-sidelobe angular filter. The non-sidelobe angular filtering based on VBGs with thicknesses of 2.5 and 2.9 mm is simulated and demonstrated. The near-field distribution of filtered beams through the non-sidelobe angular filter is obviously smoother than that of the single VBG. The near-field modulation and contrast ratio (C) of filtered beams are found to be improved 1.17 and 1.66 times that of the single VBG. The far-field C of the filtered beam is improved to about 100∶1 and the power spectral density analysis shows that the cutoff frequency of the angular filter is greatly optimized with the VBG combination.
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