【摘要】 为了准确测试和评价大口径连续相位板(CPP)元件的远场光强性能,根据激光装置需求建立了351nm波长下大口径CPP远场光强离线测试系统,开展了330mm×330mm口径CPP元件测试实验,并与标量衍射计算结果进行对比,分析了系统的测试重复性和测试精度。实测系统远场弥散斑大小为2.9倍衍射极限,可测试最大口径为圆形600mm和方形430mm×430mm。测试系统在焦点±2mm范围内的能量集中度测试重复性优于0.2%。计算和实验焦斑形貌及分布吻合,实测能量集中度比计算结果小0.85%、焦斑半径大13μm左右,差异由实测系统的时间匀滑作用引起,可通过缩短曝光时间和减小系统像差等措施进一步提高测试精度。更多还原

【Abstract】 In order to measure and evaluate the far-field intensity caused by large-aperture continuous phase plates,off-line measurement system with 351nm laser for the far-field intensity was built according to the physical demand parameters of the laser system in ICF equipment.The experiment for CPP with 330mm ×330mm aperture was carried out.The measurement reproducibility and accuracy were analyzed according to the calculated result with scale diffraction theory.The diameter of dispersion focus is about 2.9times diffraction-limited diameter and the maximal size that the system can measure is600mm or 430mm ×430mm.The reproducibility for measuring encircled energy fraction in defocusing amount±2mm is better than 0.2%.The shape and distribution from experiment accord with the calculated result,the measured encircled energy percentage is 0.85%less than the calculated result and the measured radius is 13μm larger than the calculated result,the difference is caused by temporal smoothing of the measurement system,so the measurement accuracy could be enhanced through shortening time of exposure of CCD and reducing the optical aberration of the measurement system.更多还原