Synchronous phase-shift fiso interferometer

Abstract

A synchronous phase-shifting Fizeau interferometer comprises a half-wave plate, a focusing lens, a diaphragm, a beam splitter, a first collimating lens, and a birefringent thin-film standard lens, which are arranged sequentially along the beam advancing direction of a linearly polarized laser source, wherein the diaphragm is positioned on the back focus and the front focus of the first collimating lens; a second collimating lens and a synchronous phase shifter are sequentially arranged in a direction perpendicular to the beam advancing direction of the beam splitter; the beam having a surface to be detected on the linearly polarized laser source passes through the emergent direction of the birefringent thin-film standard lens; the birefringent thin-film standard lens is a standard flat panel and has an antireflection film on the incident surface of the standard flat panel and a birefringent thin film and an antireflection film on the emergent surface; and the birefringent thin film has a phase delay of 90 DEG. The synchronous phase-shifting Fizeau interferometer has the advances of no principle return error, long measurement distance, simple structure and easy operation.

Description

technical field [0001] The invention relates to optical interferometry, in particular to a synchronous phase-shifting Fizeau interferometer. Background technique [0002] Interferometer is a non-contact high-precision measuring instrument, which has been more and more widely used in modern optical measurement. Among various interferometers, the Fizeau interferometer includes the reference arm in the measurement arm to realize the common optical path interference of the reference beam and the measurement beam. The impact of environmental factors on measurement accuracy has become the most commonly used test instrument in optical processing. In order to improve the measurement accuracy, it is necessary to introduce phase shifting technology into the Fizeau interferometer to extract the phase distribution to obtain the surface shape information. For Fizeau interferometers, the common phase shifting measures are piezoelectric ceramics driving standard mirrors to move or changi...

AI Technical Summary

Problems solved by technology

The synchronous phase-shifting Fizeau interferometer realizes the complete common optical path of the measurement beam and the reference beam, but its optical path structure is complex, the adjustment process of optical path difference is cumbersome, and the coherence of the light source is short, so it is not suitable for long-distance measurement.

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