离轴卡塞格林光学系统装调技术

介绍了一种离轴卡塞格林光学系统的高精度装配和调整方法。针对离轴抛物面主镜装配难点,通过理论计算及仿真分析,确定粘接形式及粘接面积,利用干涉仪及平面镜实现自准直检测,完成了主镜的微应力装配。结合系统结构特点,通过测量主镜最佳面型,将主镜位置姿态与机械基准建立关系,使主镜光轴与机械基准保持一致。通过分析次镜失调量与系统波相差之间的关系,对次镜进行六个自由度的调整实现系统波相差校正。主镜粘接装配后面型变化小于5%,系统装调后波像差优于0.055λ,均满足了设计指标要求。     

宽视场长焦距离轴三反射镜光学系统的设计

分析了离轴三反射镜系统成像特性．根据共轴三反射镜光学系统像差理论，确定结构参数的基本计算公式．设计了长焦宽视场的离轴三反射镜光学系统，分析了系统结构参量对像差的影响．结果表明，该系统视角较大，地面复益范围较宽，成像质量接近衍射极限．     

多视场离轴全反射式光学系统

讨论了以长焦距、宽视场光学系统为应用背景的多视场离轴全反射式光学系统。全反射式光学系统进行离轴使用,可以实现无中心遮拦,能量利用率高。在离轴全反射式光学系统中通过移动或旋转反射镜组可得到多视场离轴全反射式光学系统。分析了多视场离轴全反射式光学系统的设计基础、设计方法及特点,并给出了双视场离轴全反射式光学系统和三视场离轴全反射式光学系统的设计结果。     

大视场离轴三反光学系统场曲特性与装调方法

基于矢量波像差理论,分析了离轴三反光学系统装调过程中在小量失调状态下的场曲特性,提出了通过倾斜焦面补偿系统失调产生场曲的方法.在此基础上,结合某遥感相机进行了仿真模拟,具体分析了焦面分视场数目与三反射镜安装精度要求的关系,提出了系统装调流程和方法.利用测试相机调制传递函数的方法,对相机的场曲特性进行了测试,并通过修正焦...     

宽光谱高分辨离轴三反光学系统设计

为了解决空间对地遥感光学系统探测波段窄、分辨率低等问题,设计了一款非球面离轴三反光学系统。对计算得到的同轴三反结构进行了视场离轴处理,优化了像差,分析及评价了离轴三反系统的成像质量。设计得到的光学系统分辨率在可见光及短、中波红外波段都得到了提升,分别能够达到2 m、3.3 m以及10 m的地元分辨率,系统三个反射镜面型均为偶次非球面,焦距600 mm,相对孔径1/4.3,视场角8°×4°,最大畸变0.4%。各波段在奈奎斯特频率处的MTF值均高于0.2,且RMS半径满足小于探测器最小像元尺寸的成像要求。实现了高分辨率、宽波段的设计目标所要求的各项指标,从而提升了系统全时间段、全天候的信息获取能力。     

变焦扩束系统的光学设计

利用几何光学理论,详细分析变焦扩束系统的两,工结合实例,指出在进行光学设计时选取参数的依据。     

利用离轴三反镜光学系统确定各镜的装调公差

利用条纹泽尼克系数与赛德尔像差的关系,在三反镜光学系统的出瞳面上,用条纹泽尼克系数来表示系统的波像差。通过光学设计软件Zemax计算得到三反镜光学系统各镜的装调公差,以公差要求高的镜面作为装调基面,从而减少要调整的自由度。通过分析泽尼克(Zernike)系数在公差范围内的变化幅度来确定光学系统在出瞳面上各个像差的变化幅度,用该幅度的变化量来决定主次三镜各自由度在各个方向上的敏感度,最终确定各个自由度的优化调整级别。对一大口径无遮拦离轴三反镜光学系统进行了装调,在波长λ=632.8nm的条件下进行了检测。结果表明:整个光学系统全视场波前误差的均方根值RMS=0.108λ。     

一种新型离轴三反式光学系统的设计

在三反射镜光学系统的几何光学理论的基础上,设计了一个焦距f=1000 mm,相对孔径D/f=1/4,视场角2w=3°的离轴非球面三镜反射系统,讨论了优化方法和各参量对系统结构和像差的影响.     

多波段红外离轴三反光学系统的设计

单一红外波段的光学系统在无人机对地侦察时接收到目标信息量较少,也易受环境的影响甚至无法探测到目标,严重影响了侦察的效率.分析了多波段红外光学系统成像原理及设计方法,最终选取反射式结构形式设计了一款焦距为50mm、全视场为12°×10°的离轴三反红外光学系统,该系统可用于短波红外成像、中波红外成像,以及长波红外成像.各个...     

Propagation properties of off-axis Hermite--cosh--Gaussian beam combinations through a first-order optical system

Based on the Collins integral formula, the analytic expressions of propagation of the coherent and the incoherent off-axis Hermite--cosh--Gaussian (HChG) beam combinations with rectangular symmetry passing through a paraxial first-order optical system are derived, and corresponding numerical examples are given and analysed. The resulting beam quality is discussed in terms of power in the bucket (PIB). The study suggests that the resulting beam cannot keep the initial intensity shape during the propagation and the beam quality for coherent mode is not always better than that for incoherent mode. Reviewing the numerical simulations of Gaussian, Hermite--Gaussian (HG) and cosh--Gaussian (ChG) beam combinations indicates that the Hermite polynomial exerts a chief influence on the irradiance profile of composite beam and far field power concentration.     

某坦克炮长镜光学系统装调技术

为了解决坦克火控炮长视场稳定激光测距瞄准镜光学系统总装过程中稳像系统Z轴精度不高、校靶范围超差、装表范围超差、三轴平行性差的问题,提出炮瞄镜光学系统总装方法,通过采用光学自准直方法,将前置镜、高精度的平面反射镜工装、长焦距平行光管以及零位仪等设备调校建立瞄准轴零位基准,使三轴（瞄准轴、激光发射轴和激光接收轴）平行性的调校达标,并保证装表、校靶等有活动范围要求的光机部件的活动范围偏差合格,实现产品一次交检合格率由原来的60%提高到95%以上,产品的稳定性和可靠性得到提升,从而确保坦克火炮的首发命中率。     

Freeform lens for off-axis illumination in optical lithography system

A method of designing a freeform lens for off-axis illumination (OAI) in an optical lithography system is proposed in this paper. Based on the Snell's law and conservation law of energy, a series of first-order partial differential equations are deduced. Coordinate relations are established with the energy mapping relations by the characteristics of the incident beam and the predetermined irradiance distribution on the target plane. The contours of the freeform lens are calculated by solving partial differential equations numerically. Moreover, the optical performance for OAI is simulated and analyzed. Simulation results show that the irradiance distributions can be well controlled with a maximum uniformity of 95.71% and a maximum efficiency of 99.04%. Tolerance analysis shows that the angular errors of the freeform lens are more sensitive than the coordinate errors.     

大倍率离轴无焦四反光学系统设计

空间引力波探测任务采用的是外差法激光干涉测量技术,其对系统的噪声和精度要求极为苛刻。望远镜是引力波探测天文台的重要组成部分,起到激光信号收发的作用,其光学系统应具备大倍率、高像质、杂光抑制能力强,波前误差一致性好的特点。针对上述要求,对大倍率离轴四反无焦光学系统进行了设计和优化。基于初级像差理论阐述了初始结构的求解方法。系统具有中间像面和可用的实出瞳,便于杂光抑制和与后端科学干涉仪的承接。优化过程中,建立了波前一致性优化函数,通过优化设计,系统入瞳直径为200 mm,放大倍率为40倍,科学视场为±8μrad,波前误差RMS值优于0.005λ,PV值优于0.023λ(λ=1064 nm),波前一致性残差RMS值优于0.0008λ(λ=1064 nm),在捕获视场±200μrad内的成像质量均接近衍射极限,并对系统公差进行了分析,满足引力波探测的应用需求。     

多波段共孔径离轴三反光学系统设计北大核心CSCD

针对军用光电系统对视场范围、图像质量和系统小型化的迫切需求,根据指标要求设计了一种大口径离轴三反光学系统。采用离轴多反式结构消除系统遮拦,缩减结构尺寸,通过引入复杂面型实现大孔径设计,在保证足够分辨率的同时,增大光学系统的视场角,以获得更加丰富的目标特征,提高了系统的目标探测和识别能力。与透射式结构与折返式结构相比,大幅度减小了光电产品的体积和质量,有效减轻了伺服设计负荷,具备隐蔽性好、光谱覆盖范围广、透过率高、视场兼容性强的特点。设计结果表明:电视光路在120 lp/mm处全视场MTF>0.2,短波红外光路在60 lp/mm处全视场MTF>0.3,中波红外在30 lp/mm处全视场MTF>0.15,网格畸变小于0.5%,满足设计指标要求。     

应用于数字高速成像的离轴光学系统设计

为提高数字高速多幅相机的像面照度,简化光学系统结构,提出一种离轴光学系统设计方法。该系统使用多组相同物镜,采用圆心一组,圆周均匀分布多组的方式平行阵列排布。分布于圆周上的物镜,其像面接收器相对物镜轴心平移离轴,以获得与圆心物镜相同的物面图像。分析了单物镜像面照度、畸变等与视场有关参数对光学系统各像面匹配的影响。在此基础上给出一个5通道离轴光学系统设计实例,系统空间分辨率优于30 lp/mm,畸变小于0.1%,F数2.0。相比目前广泛采用的棱锥、棱镜分幅方式,该离轴光学系统像面照度增加5倍以上,系统结构简易。     

Manifestation of the rotational Doppler effect by use of an off-axis optical vortex beam

We report what is to our knowledge the first all-optical detection of the frequency beats between Gaussian and Laguerre-Gaussian LG0(1) modes in their axial superposition, caused by the rotational Doppler effect. The relation between the observable off-axis optical vortex rotation and the rotational frequency shift of the Laguerre-Gaussian component is ascertained. The results can be used as a physical basis for recognition of Laguerre-Gaussian mode spectra along their orbital angular momenta.     

Analysis of space off-axis and performance of Cassegrain optical antenna system

The research of optical antenna is of greatest importance in the field of modern optical communication. For optical antenna, alignment of optical system is a significant factor, which influences the transmission quality of optical antenna system. Antenna off-axis is one of the important factors influencing the transmission quality of optical antenna system. In this paper, we analyze and numerically simulate how power attenuation ratio and gain of Cassegrain antenna vary with the antenna deflection angle and the distance that the central axis of receiving antenna deviates from z-axis, when space off-axis happens to the system. Finally, the coupling efficiency of Cassegrain antenna is tested experimentally, and the results show that the coupling efficiency of the Cassegrain antenna dramatically reduces in the case of off-axis. These studies provide a theoretical basis for optical antenna system to achieve accurate alignment in optical communication.