Offner成像光谱仪的设计方法

Design Method of Offner-Type Imaging Spectrometer

基于子午和弧矢聚焦曲线给出了一种Offner型成像光谱仪的新的设计方法。该方法不但适用于三同心元件Offner型成像光谱仪,还适用于传统的两同心元件Offner成像光谱仪的设计,更重要的是该方法还可以灵活地以商品化标准光学元件为基础进行优化设计,克服了已有方法的复杂性与单一针对性。给出了采用该方法分别在子午和弧矢聚焦曲线相切、两点相交和已知元件参数进行优化的设计流程。并利用该设计流程给出了已知元件参数进行优化设计实例,在相对孔径f/3.2时,在400～1000 nm波长范围内可以得到最大的光斑半径的均方根值仅为2.3μm的追迹结果,这一数值在1000 nm时已经达到了衍射极限。采用上述设计参数成功研制出了一台成像光谱仪,经初步测试达到各项设计指标。

A new design approach about Offner-type imaging spectrometer is presented based on the relation between the meridianal focusing curve and the sagittal focusing curve.It can be not only applied to the Offner-type spectrometer with the three concentric components,but also the traditional Offner-type spectrometer with two concentric components.What＇s more,it can be flexibly optimized based on existing components,which overcomes the complexity and pertinence of the existing methods.The procedures of the tangensy and intersection relations of the meridional and sagittal focusing curres and the design of existing components are shown.An example of optimization design with the existing components is presented.With the relative aperture of f/3.2,the smallest RMS spot radius of 2.3μm at the wavelength range of 400～1000 nm can be achieved,which is very close to the diffraction limit at the wavelength of 1000 nm.An imaging spectrometer is developed successfully using the above parameters,which can achieve the indexs after preliminary test finally.