In order to improve laser transmission efficiency at 1053 nm and 527 nm, a potassium deuterium phosphate (DKDP) crystal (a key component of high-power laser systems) needs a bi-layer antireflection coating system on its incident surface. UV-curable polysiloxane coatings with a refractive index varying from 1.500 to 1.485 were prepared through the polycondensation of a methacryloxy propyl trimethoxylsilane (MPS) monomer with a controllable degree of hydrolysis. Additionally, the influence rule of the coating structure on the refractive index was intensively studied, and the primary factors that dominate the hydrolysis process were discussed. Further refractive index adjustment was achieved using only a small amount of dopant based on the polysiloxane coating with refractive index of 1.485, allowing for high antireflection of the bi-layer coating system at desired wavelengths to be achieved. In addition, high laser damage resistance and remarkable mechanical properties of the coating were simultaneously realized through the incorporation of a minor quantity of dopants, which benefited from the successful modulation of the intrinsic refractive index of the polysiloxane coating.

In order to measure the aspherical transmission wavefront of large aperture optics with wedged angle, three compensators were fabricated based on theories of geometrical and diffraction optics, a single null lens and two computer-generated-holograms (CGH) by different frequecy carrier. The results show that both refraction null compensator and diffraction plate can achieve high-precision wavefront measurement of large aperture aspherical optics, the difference of wavefront measured by refraction and diffraction methods is better than 0.01λ(RMS) in the effective aperture area. Because of the measure beam deviation caused by the optic wedge, the results is very sensitive to parts position and gesture. Due to a smaller divergence angle and extra alignment/fiducial area for precision adjustment, the primary aberrations of tilted CGH measurment can get a better control than that of null compensator. Precise control or adjustment of compensator is critical for aspherical wavefront measurement. Null compensator lens can easily induce regulation error while CGH method could cause mid-frequency disturbance.

The continuous phase plate with a large wavefront gradient is used as the far-field beam shaping element in some high-power laser physics experiments. During the fabrication of continuous phase plate and before the actual use, it is necessary to measurement its wavefront to judge the fabrication quality and whether the wavefront distribution meets the requirement of use. By constructing a novel amplitude replacement phase retrieval algorithm with variable weighting factor, fast and high precision reconstruction of CPP with large wavefront gradient can be achieved. The proposed method is validated by numerical simulation and experiment.

The fully continuous spiral phase plate (SPP) has been used more and more widely in high-power laser and other fields. Its unique jump cross section structure with a width of only a few millimeters puts forward extremely high requirements for wavefront measurement. In this paper, a defocus multi-intensity phase retrieval algorithm based on weighted GS for wavefront measurement of SPP is proposed, and the influence of phase retrieval test error on measurement accuracy is analyzed. Finally, a phase retrieval test platform is established, and the high-precision phase retrieval measurement of the SPP wavefront is realized.

For lens-free imaging technology based on axial multi-plane phase retrieval, the test parameters have a very important impact on the image reconstruction speed and quality. The deviations between the actual position of the recorded diffraction intensity pattern and the set position in the reconstruction algorithm will also affect the image reconstruction quality. We analyzed the influence of test parameters and deviations on the reconstruction accuracy and proposed a method to correct the position mismatch of the intensity image. The effectiveness of the method is verified by simulation and experiment.

In order to realize high-precision and low-cost detection of wavefront power spectral density (PSD) of large aperture optical elements, a detection method combining the interference and splicing techniques is proposed. The method for calculting the wavefront PSD is deduced, and the subaperture stitching method is proposed based on the correlation match algorithm. Then the error sources in the stitching interferometry are analyzed. The simulation by the stitching method is performed and the results show that the relative deviations of the wavefront distortion peak-valley value (dpv) and the root mean square value (PRMS) of the PSD during the stitching detection are 1.2% and 0.1%, respectively. Five experiments with 620 mmx450 mm aperture elements are accomplished and the corresponding stitching results are compared with the direct test results of the full aperture elements. The distributions are consistent with each other. The deviation of dpv is 0.012 ?(?=632.8 nm) and that of PRMS is 0.03 nm, which indicating the proposed mehtod is stable and reliable for the stiching test of wavefront PSD of large aperture optical elements?

针对强激光系统所需大口径非球面元件高精度、批量化的加工需求,提出了一种气囊抛光技术与柔性沥青小工具抛光技术相结合的大口径非球面元件高效制造方法.采用气囊抛光技术进行非球面保形抛光和快速修正抛光,实现磨削缺陷层快速去除以及低频误差快速修正.采用柔性沥青工具匀滑抛光技术,在低频误差不被恶化的情况下,控制元件中高频误差.在抛光过程中,利用球面干涉仪搭建的自准直波前干涉检测系统和粗糙度仪对非球面元件进行全频段误差检测.基于上述加工与检测方法完成了430 mm×430 mm口径离轴非球面透镜样件实验加工,实验结果为元件通光口径内透射波前PV=0.1λ,GRMS=5.7 nm/cm,PSD1 RMS=1.76 nm,PSD2 RMS=1 nm,Rq=0.61 nm,并且中频段功率谱密度曲线均在要求的评判曲线之下.实验结果表明,离轴非球面透镜样件全频段指标均达到了合格指标要求.所述制造方法也适用于其他类型大口径非球面光学元件的高精度加工.

采用高质量的标准位相结构是实现光学干涉检测系统的系统传递函数精确校准及保证光学元件波前/表面中高频段信息准确检测的前提。通过对二元伪随机光栅结构和台阶位相结构两类典型表面进行模拟,分析了空间周期误差及跃变边缘陡度等制造误差对于检测系统传递函数校准的影响,并分析了检测系统CCD对二元伪随机光栅欠采样和过采样时功率谱密度（PSD）的变化。结果表明:存在同等制造误差时,二元伪随机光栅结构比台阶位相结构对检测系统传递函数中高频能够实现更高精度的校准;当对二元伪随机光栅存在欠采样或过采样时,均会造成PSD随频率的下降,可通过对理想二元伪随机光栅的高度分布进行相应的采样修正消除因采样对传递函数校准的影响。

为了提高惯性约束聚变(ICF)激光装置中连续相位板(CPP)的焦斑性能,建立了波前畸变下连续相位板焦斑的理论计算和分析模型,并根据CPP使用条件搭建了三倍频大口径CPP远场离线测试系统.对加工330 mm×330 mm口径的CPP和波前畸变元件进行了理论计算和离线测试实验的对比研究.理论计算和实测的焦斑形貌、参数数值均非常一致,验证了计算模型的正确性和实验系统的可靠性.理论和实验结果一致表明,波前畸变对CPP焦斑性能的影响非常严重,当弥散斑为0.5倍CPP焦斑时,畸变量已对CPP焦斑形貌产生了很大影响,能量利用率下降值大于4％,焦斑半径增大超过20μm,陡边阶数下降1.3阶,不均匀性均方根(RMS)值下降6％,旁瓣份额增长超过0.5％.

大口径光学元件中频波前的准确评价已成为高功率激光系统中关注的焦点,元件中频波前均方根值是重要评价指标之一.根据波前中频检测频段及波前检测设备频响特性,将波前的中频区域分为两个检测频段,分别采用干涉仪和光学轮廓仪实现了中频波前均方根值的检测.采用大口径干涉仪可实现全口径波前中频区域低频段波前的检测,通过比对大口径干涉仪和采用小口径干涉仪结合分块融合平均方法的检测结果,提出采用分块融合平均方法也可检测相应频段全口径波前均方根.采用光学轮廓仪通过离散采样的方法检测大口径元件中频区域高频段波前均方根,针对不同离散采样方式的实验结果表明:3×3的采样方式能满足对410 mm×410 mm口径元件中频区域高频段波前均方根的检测.

在惯性约束聚变（ICF）研究过程中,焦面上聚焦光斑形态要求极为苛刻。基于离线测试平台,从实验上研究了各种应用误差对连续相位板（CPP）远场焦斑能量集中度的影响。得出光束旋转误差、口径误差、平移误差和倾斜误差在可控范围内CPP远场焦斑能量集中度均高于95%,其波动范围小于0.5%,CPP的容忍度较强。而实验畸变波前属于空间频率小于0.02mm-1的低频波前,严重影响了CPP的整形能力,波前畸变是影响能量集中度高于90%的主要因素。

In order to measure and evaluate the far-field intensity caused by large-aperture continuous phase plates, off-line measurement system with 351 nm 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 330 mm330 mm 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 2.9 times diffraction-limited diameter and the maximal size that the system can measure is f600 mm or 430 mm430 mm. The reproducibility for measuring encircled energy fraction in defocusing amount 2 mm 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 13 m 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.

对大口径连续相位板(CPP)在子孔径拼接检测过程中存在的几种影响检测精度的主要因素,包括定位误差、系统误差和拼接模式等进行了归纳并分析了其对检测精度的影响权重.通过对子孔径重叠区域分布的均匀性计算,分析了检测误差对拼接质量的影响.结果表明,定位误差是影响CPP拼接精度的主要原因,而对系统误差进行有效处理可以进一步减小重叠区非均匀性,拼接模式的选择对CPP的拼接结果的影响有限.通过CPP深度特性对重叠区域均匀性的统计分析表明,在像素级别的检测中,重叠区域均方根残差随着CPP深度的增加而线性增加,即拼接精度随CPP深度的增加而降低.

Experiments on magnetorheological finishing (MRF) were carried out to remove the subsurface defect (SSD) layer left by conventional polishing. The simulation and experiment results show that, the scanning interval of MRF will lead to the mid-spatial frequency error of corresponding frequency, the instability of the polishing spot will leave the mid-spatial frequency error of uncertain frequency, and an approximately linear correlation is found between the depth of removal and the peak value of power spectral density (PSD) of processed components. With MRF as the method to remove the SSD layer, the quality of processed components concerning the mid-spatial frequency is greatly affected by the processing settings. If a thick SSD layer is left by an inappropriate prior polishing, the PSD after MRF will exceed the limit.

The test of wavefront of large aperture continuous phase plate(CPP) is difficult to obtain by whole aperture once because of CPP's characteristic such as large phase depth and large phase gradient, so sub-aperture stitching technique is often used to test the CPP's wavefront in whole aperture. We analysed some problems in the traditional sub-aperture stitching test and put forward a new stitching model mathematically in order to improve the precision in CPP's sub-aperture stitching test. We have found that this new model is available by a serial experiments.

基于全局最小二乘拼接算法和图像融合算法建立了连续相位板(CPP)子孔径拼接检测算法,并根据全局相关匹配原理提出采用面形残差来评价CPP的加工面形.采用高精度动态干涉仪等设备建立了相应的检测系统,并针对430mm×430mm口径CPP开展了数值模拟和检测实验.理论计算结果表明:系统计算误差为0.005nm.实验结果表明,整个检测系统软硬件RMS误差小于5nm,基本满足CPP面形检测要求.从而验证了CPP检测和评价的正确性和可行性.

在高功率激光系统中,大口径元件的中频波前影响系统的安全运行,中频波前均方根（PSD1）是用来评价中频波前质量的关键参数。由于大口径干涉仪在系统传递函数（STF）上不能完全满足中频波前的检测要求,提出采用小口径高分辨率干涉仪检测的统计分析方法,建立了统计理论模型,分析了测量不确定度。建立了子区域PSD1检测装置,提出了子区域倾斜补偿法,提高了检测精度。理论及实验结果表明针对400mm×400mm分析区域,子区域数量设置为4×4,置信水平为95.4%时,测量不确定度为±0.266nm。该方法与大口径干涉仪检测法的对比实验表明,400mm×400mm分析区域内检测结果偏差小于5%。子区域统计分析法是对大口径干涉仪检测法的有益补充,对先进光学制造工艺的优化具有重要的参考价值。

A statistical method is proposed to measure the power-spectral density (PSD) of the mid-spatial frequency defects of large optics. The method measures the geometrical defects of large optics by a large-aperture low-resolution interferometer, and then measures the mid-spatial frequency defects of every subregion in large optics by a small-aperture high-resolution interferometer. Statistical theory shows that the PSD of mid-spatial frequency defects in large optics approximately equals the weighted average of that in every subregion. Simulation and experiment demonstrate the effectiveness and feasibility of the proposed method. The proposed statistical method is not sensitive to the translation stage's error and thus is more appropriate for measurement of the mid-spatial frequency defects of large optics than the traditional sub-aperture stitching interferometry.

连续相位板（CPP）是大型激光装置中用于控制光束形状、能量和波前分布的一种重要衍射光学元件。为改善聚焦光束的质量,建立了基于现有工艺的大口径CPP理论设计模型,优化了传统衍射元件设计算法。采用该算法设计了用于背光照明的Ф330mm CPP,开展了数控化学抛光制作CPP试制,并在大型激光装置上开展了验证实验。结果表明,基于工艺改进算法设计的CPP具有更好的加工特性和焦斑性能,基本实现了整形和匀滑性能,能够较好满足现有工艺约束条件和物理需求。

在高功率激光系统中,大口径连续相位板（CPP）元件是用来进行光束整形的关键衍射光学器件,由于其毫米量级的空间周期、大相位梯度的波前特征,大口径干涉仪无法满足检测需求。提出采用小口径高分辨率干涉仪结合子孔径拼接实现相位板元件透射/反射波前的检测,采用了误差均化的拼接方法,设计了针对圆形孔径的数据融合新算法,研制了子孔径拼接检测装置,实现了一块330 mm×330 mm的连续相位板元件透射波前的检测。实验结果表明,针对其毫米量级的周期,最大可检测到的波前梯度接近3μm/cm,检测重复性精度优于6 nm[均方根（RMS）],波前数据模拟焦斑计算结果与高功率激光系统中的远场焦斑特性检测结果获得了较好的一致性。