Small-F number multi-wavelength standard spherical reference lens assembly

Abstract

The invention discloses a small-F number multi-wavelength standard spherical reference lens assembly. The small-F number multi-wavelength standard spherical reference lens assembly adopts the working wavelengths of 632.8 nanometers, 543.5 nanometers and 532 nanometers; achromatism of the lens assembly is achieved by using low-chromatic dispersion crown glass ZK7 and high-chromatic dispersion flint glass ZF6; the small-F number multi-wavelength standard spherical reference lens assembly adopts a three-piece lens design, and consists of a doublet positive lens, a negative lens, and a positive lens with a standard spherical surface as the last surface; the caliber, the F number and the top focal length design theoretical value of the reference lens assembly are 100mm, F / 3 and 254.7mm respectively; except for the last mirror surface of the reference lens assembly, the other mirror surfaces are plated with three-point antireflection films with the wavelengths of 632.8 nanometers, 543.5 nanometers and 532 nanometers; through combination of the doublet positive lens and the negative lens, an approximately afocal feature of an optical structure is achieved, the sensitivity of the change of a coincidence error between a focal point and the curvature center of the last surface along with the change of a mirror spacing is reduced, and installation and adjustment of the small-F number standard spherical lens assembly are facilitated.

Description

technical field [0001] The invention belongs to the field of optical instruments, and in particular relates to a small F-number multi-wavelength standard spherical reference lens group. Background technique [0002] Optical interference testing technology has a very wide range of applications in the surface shape of optical components, the characteristic parameters of optical materials and the performance testing of optoelectronic systems due to its advantages of high precision and non-contact non-destructive measurement. [0003] Yeou-Yen Cheng et al. proposed the principle of two-wavelength phase shifting interferometry in "Two-wavelength phase shifting interferometry" (APPLIED OPTICS, 24(23): 4539-4543, 1984). By solving the synthetic wavelength phase, the single While the wavelength phase-shifting interferometer has a test range, it can retain high test accuracy. [0004] When the interferometer detects the spherical surface shape, it needs to be equipped with a standar...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a small F-number multi-wavelength standard spherical reference lens group, which solves the problem that the traditional standard spherical reference lens group can only be used for single-wavelength detection, and also solves the difficulty in adjusting the standard spherical reference lens group. question

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