Ultrasonic tunable spectral interferometry device and measurement method

Abstract

A measuring device and method for ultrasonic tunable spectral interferometry. The measuring device includes an ultra-broad spectrum laser light source, a circulator, an ultrasonic generator, a transducer, an aluminum plate, a fiber Bragg grating, an optical fiber fine-tuning frame, a light trap, Beam expander output mirror, splitter prism, CCD camera, collimator lens, transmission standard mirror, DUT and standard mirror. The ultra-broad-spectrum laser light source produces a wide-spectrum beam. The ultrasonic generator and transducer are used to generate ultrasonic waves with adjustable frequency. The aluminum plate transmits ultrasonic waves to modulate the Bragg fiber grating. Separated from the grating reflected beam, a light trap is used to absorb the grating transmitted light, and a CCD camera is used to record the interferometric phase map. In the measurement process, the invention can realize the adjustment of the coherence length of the light source by adjusting the magnitude of the ultrasonic frequency, thereby realizing the fast and synchronous measurement of the surface shape error of the front and rear surfaces of the high-parallel flat plate element.

Description

technical field [0001] The invention relates to the field of ultrasonic interferometry, in particular to changing the coherence length by tuning the spectrum to realize the rapid and synchronous measurement of the front and rear surface shape errors of high parallelism flat plate components. Background technique [0002] With the rapid development of modern optical technology, modern optical systems have increasingly high requirements for the surface quality of optical components. High-quality surface optical components require high-precision detection technology to characterize. processing is also crucial. [0003] At present, the relatively mature detection methods include light interferometry measurement, microscopic interferometry measurement, light section measurement, light scattering measurement and optical stylus measurement. Among them, optical interferometry measurement is mainly based on point diffraction interferometry and Fizeau interferometer measurement. Alth...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem of parasitic fringes caused by multi-surface interference of high-parallel flat plate components, and to provide an ultrasonic adjustable spectral interferometry device and measurement method for the rapid measurement of front and rear surface shape errors of multi-surface high-parallel flat plate components

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