宽谱段光学系统消二级光谱的设计

利用修正的部分色散(P)和阿贝数(V)公式,计算一些典型的普通光学玻璃在450nm～950nm波段的色散特性,应用二级光谱理论,采用普通光学材料,设计了一个复消色差系统,分析近红外波段光学系统的二级光谱特性及校正方法,给出设计实例。设计结果表明:在可见光近红外波段,采用重冕玻璃ZK4、ZK8和特种火石玻璃TF3组合实现了二级光谱色差的校正,即从理论的0.18mm减少到0.084mm,证明该系统有较好的消色差能力,并且具有较长的后截距,为安装像移补偿反射镜提供了方便。     

宽谱段折射式长焦光学镜头

介绍了宽谱段、折射式长焦镜头的光学设计.重点讨论了宽谱段(420～900 nm)二级光谱的校正问题,修正了部分色散（P）和阿贝数（V）的计算公式,使之适合于宽谱段光学系统的设计,并给出了设计实例及设计结果.本系统理论上的二级光谱约为1.2 mm,而设计结果使三条谱线（420 nm、600 nm、900 nm）基本交于一点,实际二级光谱约0.23 mm.     

宽谱段近红外星敏感器光学系统的设计

近红外波段测星已成为星敏感器的重点发展方向之一,针对近红外星敏感器使用波段宽的特点,依据消二级光谱理论中可行的两种消二级光谱方法,采用选取相对部分色散系数相同或接近、色散系数相差较大的玻璃组合的方法对近红外星敏感器光学系统进行设计。设计了一组工作波长为900 nm ~1 700 nm,F数为1.5,焦距为150 mm的光学镜头,该镜头在宽光谱范围内实现了二级光谱的校正,在空间频率等于32 lp/mm时各视场MTF均大于0.65,使系统具有良好的像质,能够满足近红外波段的测星要求。     

关于二级光谱问题的探讨

本文从波差理论出发,由前组色差引起的后组入射光线座标变化,导出了衍生二级光谱计算公式,并应用于分离薄透镜系统,得到了简明的结论。本文又把等效玻璃概念的应用加以推广,提出了用普通玻璃密接薄透镜组校正二级光谱的设计方法.     

利用本征色差校正二级光谱

一个消色差的透镜系统可由若干个互相贴合的或互相分离的、由冕玻璃和火石玻璃组成的组元组成。从理论上讲,如果使每一组元产生一定量的色差,并使色差的正或负与玻璃的选择满足一定的关系,则整个透镜系统的二级光谱可减小到任意值。本文给出了利用这一原理设计的、校正了二级光谱的两个三片复杂化型物镜实例。焦距为1.5米,相对孔径为1:7,视场角分别为15°和18°。其中一个物镜完全采用了普通玻璃。     

利用二元光学器件消二级光谱设计

二元光学器件除了能减小成像系统的体积、重量和成本外,还具有许多传统光学元件无法比拟的优越性,如独特的色散特性。通过采用基于二元光学器件的折衍射混合设计以及等效玻璃的方法,设计了长焦距宽波段望远系统,并对其二级光谱进行校正。最后通过光学软件模拟结果表明:利用二元光学元件能很好地实现消二级光谱,并且实现了系统的轻量化。     

基于S-L图的复消色差方法

建立了一组既消位置色差又消二级光谱的方程组,即复消色差方程组.同时引入了规化位置色差系数L和规化二级光谱系数S的概念,得到了对复消色差光学系统设计中的玻璃选择具有指导意义的S-L图.最后给出了应用这种方法进行的三片型透镜组和Petzval型透镜组的复消色差设计过程.     

复消色差的短波红外望远物镜设计

分析计算了一些普通光学玻璃及晶体光学材料在0.9~2.5 μm短波红外段的色散特性.在远距型的物镜结构后组中采用的厚弯月镜能产生一定量的反向色差补偿前组中的二级光谱,所设计的物镜在焦距800 mm时的带孔径处最大色差0.13 mm.结果表明,采用氟化物玻璃与重火石玻璃的三片式组合在短波红外段具有较好的消色差能力.     

环境温度和气压变化对象面位移的影响与二级光谱校正

说明利用本征色差校正二级光谱的方法,不仅可以用普通玻璃校正二级光谱,而且可以同时降低环境温度和气压变化对光学系统象面位移的影响.     

折射率、色散变化量与宽谱段傅氏镜二级光谱变化量的分析

介绍了宽谱段傅里叶变换镜头中光学玻璃的折射率、色散变化对系统的成像质量的影响.推导了折射率、色散变化量所引起的光学系统二级光谱的变化量公式.重点讨论了在宽谱段光学系统中，光学玻璃在折射率、色散上的变化量，所造成的胶合薄透镜的二级光谱的变化量.其系数在本文例中达0.28，相当于变化量占理论二级光谱余量的28％，因此在宽谱段系统中的二级光谱余量的变化量不应该被忽略.实例表明光学玻璃的折射率、色散变化量对宽谱段傅里叶变换镜头的成像质量有显著的影响.此外，还考虑了傅里叶变换透镜的波像差问题，其设计值小于1/10波长，采用最优玻璃对组合，可以保证波像差小于1/10波长，完全满足使用要求.     

Design of apochromatic telescope without anomalous dispersion glasses

A novel lens system with correction of secondary spectrum without using anomalous glasses is presented. The lens system comprises four separated lens components, with three of them being subapertures. Two examples of apochromatic telescope are presented, both with the use of typical normal glasses, namely crown K9 and flint F5 glasses, and low-cost slightly anomalous dispersion glasses. Secondary spectrum and other chromatic aberrations of the two design examples are corrected.     

衍/折射光学元件消二级光谱的设计

 采用衍/折射光学元件结合的方法，使用两种玻璃设计了星载用长焦距望远物镜，对其二级光谱进行了校正。具体介绍了衍/折透镜望远透镜消二级光谱方法、步骤。计算机模拟结果表明：校正后的望远物镜轴上位置色差小于0.08mm，满足使用要求，并且设计方法步骤简单。     

Secondary spectrum correction with normal glasses

It has been generally accepted that the correction of secondary spectrum aberrations, in optical imaging systems, necessarily requires the use of glasses having abnormal relative partial dispersions. This is shown to be an error, arising from defects in the accepted theory of first order chromatic aberrations. The theory of secondary spectrum correction with normal glasses is given, with a numerical example of its application.     

A hybrid doubled achromat based on a photon sieve

Photon sieves are diffractive optical elements with large chromatic aberration. To correct the dispersion of a photon sieve, a novel hybrid doubled achromat combined a photon sieve and a refractive lens is proposed. The design of this achromat applies the opposite dispersive characteristics of diffractive and refractive elements. Two design examples for different bandwidths of 300 nm and 80 nm in visible spectrum are given. For analyzing their focusing properties, the intensity distributions both along the axis and at the focal plane are studied. The results illustrate that the achromatic design is achieved and the secondary spectrum can be corrected for a narrow bandwidth. And compared to traditional hybrid achromat, it can focus to a sharper spot.     

宽光谱长焦距物镜的复消色差设计

介绍了以摄远型为初始结构的宽光谱长焦距折射式物镜的设计方法。对玻璃材料的选择进行了分析,并建立了能够分配三分离透镜组光焦度的复消色差方程组。通过理论计算和ZEMAX光学设计软件的优化,给出工作波长范围在0.4~0.9μm、焦距为400 mm、视场角为6.2°、相对孔径为1∶4的设计实例。设计结果表明,二级光谱得到了很好的校正,像质优良。     

Calibration of the spectral sensitivity of instruments for the near infrared region

We present an analysis of methods for calibration of the spectral sensitivity of instruments in the near IR region of the spectrum (0.90–2.05 μm), using as an example recording of the luminescence spectra of PbS semiconductor quantum dots using a diffraction monochromator and an InGaAs photodiode as the detector. We show that when high-sensitivity detectors are employed for calibration using the emission spectrum of an ideal black body, the problem of attenuation of the radiation flux is still important. Instead of neutral density glass and mesh light filters for attenuation of the radiation, we propose using UFS ultraviolet optical glasses (together with PS purple glasses), the maximum optical density of which is within the region of maximum spectral sensitivity of InGaAs photodiodes. We give examples of spectral calibration, taking into account instrumental characteristics and the effect of absorption by water vapor in the air, and also corrections of the luminescence spectra of quantum dots.     

透射式内调焦宽光谱光学系统的设计与分析

为了在实现系统内调焦的同时保证宽光谱系统的优良像质,通过合理选材对宽光谱光学系统中存在的位置色差以及二级光谱进行校正,并提出了一种内调焦宽光谱光学系统的设计方法.建立内调焦消色差的数学模型,推导系统设计所需满足的公式.结合提出的数学模型与推导出的公式,以焦距为90mm、F数为2.8、具备内调焦功能的宽光谱光学系统为例进行验证.结果表明,系统可在420~900nm的宽光谱范围内对0.2~200km位置内的目标进行色差校正,验证了内调焦宽光谱光学系统设计方法与消色差数学模型的正确性.     

Design of liquid-glass achromatic zoom lens

Optical liquids are ideal materials for designing apochromatic lens due to their lower refractive index and higher Abbe numbers than those of the ordinary optical glasses. Based on the Buchdahl dispersion formula, the dispersion coefficient diagram of liquids and glasses is established. The liquid-glass combination lens(LGCL) with small secondary spectrum is obtained by calculating the combination structure with low dispersion liquid and glasses. The initial optical structure of the liquid-glass apochromatic lens(LGAL) can be obtained by replacing two glass lenses in an initial optical system with the LGCL. Using the multi-configuration optimization of ZEMAX, the liquid-glass achromatic zoom lens (LGAZL) can be designed by optimizing the LGAL. The LGAZL has an objective field of view ?63 mm–?57 mm, an image field of view 8 mm, a working distance 240 mm and the zoom range of focal length 75–85 mm. The chromatic aberration and the secondary spectrum of the LGAZL are all less than 3 μm in the whole zoom range.