排序方式: 共有123条查询结果,搜索用时 18 毫秒
1.
A method is proposed to optimize the recording structure of the photorefractive volume grating to compensate high spatial frequency in the distorted wavefront by optical phase conjugation. Based on the coupled-wave equation, the diffraction efficiency of the recorded grating formed by the scattered beams in different recording structures is simulated. The theoretical results show that the recorded modulations with high spatial frequency can be significantly improved in the small recording angle. In the experiment, three recording structures with the recording angles of 7.5°, 30°, and 45° are chosen to verify the compensation effect. Compared with the reconstructed image in the large recording angle of 45°, the signal to noise ratio of the image recorded at 7.5° increases to 3.2 times of that at 45°. 相似文献
2.
朱健强 杨朋千 张艳丽 刘诚 周申蕾 刘志刚 唐顺兴 郭爱林 樊全堂 刘代中 张国文 孙明营 焦兆阳 张燕 康俊 焦翔 张雪洁 任志远 潘良泽 黄大杰 张笑琪 朱坪 华能 姜卓偲 王良玉 杨雪莹 杨富丽 张琰佳 林炜恒 《光学学报》2023,(8):76-100
高功率激光装置是一个复杂的有源巨型光学工程,其性能指标要求逼近科学技术与物理极限。驱动器研制有物理设计、工程光学和结构工程设计三大过程,工程光学在其中起着重要作用。高功率激光装置工程光学设计需遵循其特有的设计原则和要点,以保证装置的高性能。根据驱动器设计指标和设计特点,从总体光学设计、光束质量控制以及光束打靶精度控制方面,综述了高功率激光装置工程光学设计中的关键科学技术问题以及相应解决方法,为未来高功率激光驱动器的发展提供必要的工程设计参考。 相似文献
3.
在激光惯性约束核聚变(ICF)精确打靶中,对激光束变换、整形和控制要求苛刻,通过数字在线操控技术能够在线实现激光系统的自动校准,而频率变换是数字在线操控技术中的关键一环。在不进行逼近迭代计算的情况下,基于可逆的傅里叶变换和龙格-库塔算法,对神光II终端靶场系统中负单轴晶体KDP的"I+II"类频率变换的逆问题进行了探讨和相应的算法研究,并给出了对应的模拟计算结果。最后,与神光装置运行的实验数据进行比对,验证了频率变换逆问题算法的正确性和稳定性。 相似文献
4.
A dynamic beam propagation model of micro-vibrating spatial filters in inertial confinement fusion(ICF) facilities is built based on the additional beam in SG-II facility.The transfer matrix is then deduced,and the sensitivities of the beam positioning to the pellet in the target area to the vibrations of every spatial filter are analyzed,which indicates that the vibrations of spatial filters in the pre-amplify zone has less effects on beam positioning stability at the target.In addition,the vibrations of spatial filters in the main amplify zone dominates the beam positioning stability of the target,especially the vibration of the spatial filter SF7. 相似文献
5.
A modified extended-ptychographical-iterative-engine (ePIE) algorithm is proposed to overcome the dis- advantages of ePIE technique and reduce the influence of stage hysteresis or backlash error. The exit wave of a rotatable "screen" illuminated by plane wave is used as the illumination on the specimen, and the complex transmission functions of the rotatable object and specimen can be simultaneously reconstructed. Compared with the standard x - y scanning PIE algorithm, the proposed algorithm can completely avoid the influence of stage hysteresis (or backlash error). The proposed algorithm also has higher convergence s!oeed and better accuracy than the standard PIE algorithm. 相似文献
6.
7.
A new technology of lightning location is described, which is based on detecting the state of polarization (SOP) fluctuation of the laser light in the optic ground wire (OPGW). Compared with the conventional lightning location method, the new method is more accurate, more stable, and cheaper. Theories of Stokes parameters and Poincare sphere are introduced to analyze the SOP at the lightning strike point. It can be concluded that although the initial points of SOP on the Poincare sphere are random, the SOP fluctuation generated by lightning strike can still be accurately identified by detecting the velocity of polarization motion. A new algorithm to quantify the velocity is also introduced. 相似文献
8.
A digital holographic method that can be used for the simultaneous measurement of slopes of a deformed object in different directions is described in this paper. In this method, two holograms are recorded numerically under the normal and deformed states of the specimen, and two object waves are numerically calculated from these two holograms. The slopes corresponding to different directions are measured by superposing the two object waves with appropriate shifts. It is a superior method in regard to the simple experiment setup, the flexibility in handing the data, and the high quality phase maps. 相似文献
9.
理论分析用二种不同材料组成复合色散棱镜的色散量,提出变相色散棱镜,以增大色散量。结论在实验中得到验证。 相似文献
10.
1 Introduction Stressanalystsareofteninterestedinthederivativesofthedisplacementratherthanthedisplacementitself ,becausestrainsandhencestressesarefirst orderderivativesofdisplacement.Thederivativescanbeobtainednumericallyfromthedisplacementdatabutthep… 相似文献