全息光栅拼接参数需要用参考干涉条纹来检测。系统像差会造成干涉条纹扭曲, 产生光栅拼接误差。为补偿像差造成的光栅拼接误差, 对像差与干涉条纹扭曲量之间的理论关系进行了研究, 利用计算机模拟了参考干涉条纹图像, 并将光栅拼接误差预调制到参考干涉条纹图像中。为验证该方法的有效性, 在曝光系统像差峰-峰值为0.72λ的情况下进行了光栅拼接实验, 在光栅拼缝处像差造成-1级衍射波面最大突变量为0.36λ。利用预制参考干涉条纹图像作为拼接参考时, 其最大突变量为0.097λ。实验结果表明, 在曝光系统像差较大的情况下, 干涉条纹预制法能够有效地控制光栅拼接误差。

激光约束核聚变系统需要大口径脉冲压缩光栅。全息光栅拼接法是制造大口径光栅的重要手段。针对有像差的全息曝光系统，提出了一种拼缝处光栅对准拼接方法。为研究像差对光栅拼接特性的影响，用随机波面进行了光栅模拟拼接，计算了远场衍射能量分布与拼接误差的关系。实验拼接了（150+150）×200 mm2口径光栅，其拼接均方根误差值为0.034λ，峰-峰误差值为0.110λ。利用光栅±1 级衍射波面，计算得到了曝光系统像差，并模拟了拼缝处最小拼接误差，其均方根误差值为0.016λ，峰-峰误差值为0.105λ。结果表明，拼接误差与理论模拟结果相近。该误差不会造成远场衍射光斑能量明显下降。由此证明了该方法的可行性。

The capability of chirped-pulse compression and beam focusing of an object-image-grating self-tiling grating compressor is demonstrated in an optical parametric chirped-pulse amplification laser for the first time. Probe lasers for tiling error adjustments, which are generally required by the traditional tiled-grating compressor, are not needed in our demonstration any more. With the aid of the double-sized effective optical aperture of the second grating in the compressor, a 490 fs near-transform-limit pulse duration and a 90 μm near-diffraction-limit focal spot are obtained, synchronously, which are very close to the ones achieved by a non-tiled grating compressor with equal-sized individual gratings.

光栅拼接是解决光栅口径限制的一种有效途径，而光栅拼接的难点是子光栅的精密调整和稳定性保持。为实现子光栅的精密调整，采用了差动螺纹和压电驱动器两级驱动调整机构，子光栅调整精度可达纳米量级；为提高光栅拼接架结构稳定性，对影响光栅拼接架结构稳定性的因素进行了理论分析，根据分析结果,设计了新型的光栅拼接架，采用整体式支撑结构以提高光栅拼接架的固有频率，用柔性铰链代替弹簧以提高子光栅与光栅支撑架的联接刚度，光栅拼接架的稳定性得到大幅提高。经实验测试，拼接架的稳定时间超过1 h，子光栅间相对位移标准差为35.7 nm，拼接架满足使用要求。

针对平行光栅对结构的压缩器和圆形入射光束，建立了光栅拼缝所引起的光谱剪切的数学模型，并模拟了该光谱剪切对压缩脉冲信噪比的影响。与双曲正割型脉冲相比，光栅拼缝对高斯型脉冲信噪比的影响较小。随着光栅拼缝宽度的减小与光束口径的增大，压缩脉冲信噪比得到提高。对于确定的拼接光栅压缩器和光束直径，当脉冲中心波长与光谱剪切中心波长（受到光谱剪切作用的波段的中心波长）相等时，可以得到最高的压缩脉冲信噪比。

提出了一种大口径高精度2×2阵列光栅拼接结构，采用模块化和框架式结构设计，保证拼接结构的稳定性；设计了差动螺纹微调组件与压电驱动器相结合的微纳调整组件结构，实现拼接光栅微纳量级的调整要求；讨论了关键组件的设计和制造问题。设计制造的2×2阵列光栅实验样机的最大相对共面误差为17 μm，微纳调整组件的最小调整精度可以达到1.8 nm，分辨力为0.9 nm，初步光路实验表明，设计的拼接调整机构可以快速实时地调整2×2阵列光栅达到要求的精度，且稳定时间大于1 h。

光栅拼接是解决光栅口径限制的有效途径，而结构稳定性成为光栅拼接研究中面临的主要难题。目前使用的光栅拼接架稳定性不能完全满足实验需要，为明确影响光栅拼接稳定性的主要因素，采用多通道振动测试仪对环境振动进行了测试，结果表明供热通风与空气调节(HVAC)振动是影响光栅拼接架稳定性的主要因素；采用实测功率谱作为激励，对光栅拼接架进行了优化分析，分析结果表明增加结构阻尼比可以降低拼接架动态响应；根据有限元分析结果，采用高阻尼材料对拼接架运动结合面的连接状态进行了改进，实验表明改进后的光栅拼接架动态响应大幅减小，同时稳定时间得到延长。

Alignment errors of sub-aperture gratings in the optical design of tiled gratings and tiled grating compressors are almost unavoidable. It is important to study the relation between alignment errors and temporal properties of the tiled graing. Analyzed by pulse compression theory, the relation between these alignment errors and focused pulse width broadening is obtained. And the numerical calculation results show that planar alignment errors have much more important influences on the pulse duration, which must be controlled within 21.08 μrad, and the groove-width difference also affects the pulse duration severely, so the ratio between the groove-width difference and groove-width must be controlled within 10-5. From the point of view of eliminating angular dispersion, the planar tilt errors and groove parallelism can ompensate each other, and the groove-width difference and planar errors of tip can also compensate each other.

To obtain a large-aperture high damage threshold grating compressor for a perawatt laser system, the multi-piece dielectric membrane tiled grating is an effective method. In order to avoid the influence of tiling error on the temporal and spatial characteristics of grating, the rotation error needs to be controlled in 1 μrad. Therefore, the zero-order and first-order diffracting light is used to monitor the rotation error independently. 0.1 pixel accuracy can be achieved by location of the center of fringe with quadratic curve-fitting, which can detect rotation error about 0.5 μrad. For the requirement of high precision is confined by the controlling device and environment, real-time monitoring and adjusting are necessary to maintain the grating posture, and feedback the deflection to the installations to maintain the sub-grating position. The deviation can be maintained within 0.5 μrad for a long time. Experiments show the rotation error real-time monitoring and adjusting about tiled gratings can meet precision and stability requirements.

为了获得拍瓦激光系统需要的大口径高破坏阈值光栅压缩器,用多块电介质膜光栅进行拼接是解决问题的有效方法。旋转偏差需要控制在1 μrad内,才能避免拼接误差带来的时空特性影响,因此利用零级光和一级衍射光对旋转偏差进行独立监测,采用二次曲线拟合法对干涉条纹中心位置进行高精度测量,测量精度可达0.1 pixel,检测到旋转偏差约0.5 μrad;高精度的要求受调节机构和环境的限制,需实时监测调节来保持光栅姿态,将偏转量反馈给光栅调节装置保持拼接子光栅的位置,可长时间保持在0.5 μrad偏差内。实验结果表明,光栅拼接旋转偏差实时监测调节能满足拼接高精度和长时间稳定的要求。