A method and system for dual-channel simultaneous spatial domain and time domain polarization phase shift interference

Abstract

The invention relates to a double-channel same-time-space-domain and time-domain polarization phase shift interference method and system. The method comprises that electronic equipment controls two image sensors to collect two phase-shift interferograms; the electronic equipment controls a spatial light modulator to introduce one random phase shift; the electronic equipment controls the two imagesensors to collect two other phase-shift interferograms; and the electronic equipment obtains the four phase-shift interferograms and phase shift amounts thereof, and calculates the phase of an article to be measured according to the four phase-shift interferograms and phase shift amounts thereof. According to embodiments of the invention, operation can be simplified, the environment interferenceresistance is improved, the system and method can be applied to measurement of any unknown phase shift amount effectively, calculation of the phase shift amount is avoided, phase measurement within one stripe can be realized simply and rapidly in high precision, influence of the amount and shape of stripes is avoided, and phase measurement in the vibration environment and dynamic phase measurementof a slow varying object are realized.

Description

technical field [0001] The invention relates to the field of optical interferometry or digital holographic measurement, in particular to a dual-channel simultaneous space domain and time domain polarization phase-shifting interference method and system. Background technique [0002] Due to its advantages of non-invasive, non-destructive, high-precision, full-field and fast measurement, phase-shift interferometry technology has been widely used in precision optical component detection, fluid dynamics, biological cell detection, refractive index measurement, digital holography And quantitative phase imaging and many other fields. [0003] In the phase-shift interferometry method, the traditional time-domain multi-step phase-shift method has the advantages of simple algorithm, less calculation, and high precision. It is easily affected by external vibration, air turbulence and laser power changes, and the phase shift between holograms is required to be known or the phase shift...

AI Technical Summary

Problems solved by technology

Although these methods can maximize the use of spatial resolution, they require more sensors, so the method has a complex structure and is difficult to implement.

[0006] With the development of phase shift interferometry, another type of self-calibration algorithm based on the relationship between interference fringe patterns has been proposed. This type of method can directly calculate the phase to be measured under any phase shift, but this type of algorithm is very expensive. , and there are certain requirements on the number and uniformity of interference fringes, and the two-step demodulation method is also affected by background item elimination. It can be seen that this type of method has high requirements for implementation and is susceptible to environmental interference

Images