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

Analysis on Increment of Index of Glass and Increment of Secondary Spectrum of the Wide Bands FT Lens

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.

The effect induced by the increment of refraction index and dispersion of glass in the wide bands FT（Fourier Translate） lens were introduced. The formula of the increment of secondary spectrum which brought by the increment of refraction index and dispersion of glass were deduced. The increment of secondary spectrum of thin double lens in wide bands system was emphatically discussed. In this thesis, the coefficient of the increment to secondary spectrum is 0.28, which is said this increment is about 28 % of the theory secondary spectrum of thin double lens, so it should not be ignored by any designer. The example showed in this thesis indicated that the increment of refraction index and dispersion of glass in the wide bands system had more serious effect to its imaging quality. In addition, the FT lens wavefront aberrations were mentioned,and the wavefront aberrations were designed less than 1/10 waves in the using bands. When the best glasses couple were used to produce the FT lens, the wavefront aberration could be remained less than 1/10 waves. So it can be considered that the lens could meet the use to disposal the optical information, if the FT lens could be made by the best glasses couple. The imaging quality of this FT lens is more excellent.