Phase defect detection system and method based on short-phase dry-dynamic Twyman interferometer

Abstract

The invention discloses a phase defect detection system and method based on a short-phase dry-dynamic Twyman interferometer. The system comprises two parts including a short-phase dry polarization light source and a polarization Twyman interferometer. The method comprises the following steps: firstly, enabling a light beam emitted by a short-phase laser device to pass through a polaroid and a half-wave plate and enter a Michelson interference structure; emitting a pair of linearly polarized light with orthogonal polarization directions and coupling the pair of linearly polarized light into a polarization-maintaining optical fiber; taking the linearly polarized light as a light source of a main interferometer; then adjusting a PZT (Piezoelectric Transducer) to be matched with phase difference of an interference cavity of an interferometer main body part; compensating phase delay between reference light and testing light; finally, acquiring four interference figures with the phase shifting amount difference of pi/2 in sequence by utilizing a polarization camera; solving through a phase-shifting algorithm to obtain information of phase defects. The phase defect detection system and method, disclosed by the invention, have the advantages of large view field, high resolution ratio, good shock resistance and simplicity in operation and can be used for real-time and high-precision detection of the phase defects of an optical element.

Description

technical field [0001] The invention belongs to the technical field of optical interferometric measuring instruments, in particular to a phase defect detection system and method based on a short-coherence dynamic Taiman interferometer. Background technique [0002] The defects of optical components can be divided into amplitude defects and phase defects. During application, amplitude defects in optical components can cause energy scattering, while phase defects can cause the energy of the transmitted beam of the optical system to converge, thereby destroying optical components or coatings. Especially in high-power laser systems, phase defects on optical components are the main cause of laser damage. [0003] In recent years, the measurement of nano-scale defects has attracted more and more attention, so the demand for precision measurement instruments with high resolution and large field of view is increasing. The Line Scanning Phase Differential Imaging (LPDI) proposed by...

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Problems solved by technology

Among them, PSDI is a point diffraction interferometer with a double-fiber structure proposed by Johnson. The disadvantage of this structure is that the distance between the two fibers is too strict. To ensure that the frequency of the linear carrier frequency stripes cannot exceed the sampling frequency of the CCD

This method has a simple structure and will not introduce defect interference from other components, but there are still so...

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