Method and system for measuring spatial correlation structure of partially coherent light

Abstract

The invention relates to a method and system for measuring a spatial correlation structure of partially coherent light. The method comprises: disturbance is introduced into a to-be-measured light source, porous array structure outputting is carried out and then Fourier transform is carried out, and a light intensity of the light source transmitted to a Fourier plane is recorded; no disturbance is introduced into the to-be-measured light source, porous array structure outputting is carried out and then Fourier transform is carried out, a light intensity of the light source transmitted to a Fourier plane is recorded; inverse Fourier transform and screened array filtering are carried out on the light intensities recorded in disturbance and non-disturbance states, results after filtering are subtracted, and then an obtained result is transmitted to a light source plane in an inverse manner, so that a cross-spectral density function of the light source plane is obtained; and then according to a relationship between a correlation structure function, the cross-spectral density function, and a source field light intensity, a correlation structure of the light source is obtained. Therefore, complete real-part and virtual-part information of the spatial correlation structure of the to-be-measured light source can be obtained simultaneously.

Description

technical field [0001] The invention relates to a method and system for measuring the spatial correlation structure of partially coherent light. Background technique [0002] While the laser has high coherence, it will also introduce some noise, while the low coherence laser beam has unique advantages in many aspects, such as overcoming the speckle effect in nuclear fusion and increasing signal noise in atmospheric communication. Than wait. The most classic partially coherent laser beam is the Gauss-Scher mode beam, whose spatial correlation structure conforms to the Gaussian distribution. Based on the early research of F.Gori et al., a large number of models of partially coherent laser beams with special spatial correlation structures have been proposed , for example, a Laguerre-Gaussian correlated partially coherent laser beam, a Hermitian-Gaussian correlated partially coherent laser beam, and the like. Compared with the traditional Gauss-Scher mode partially coherent la...

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Problems solved by technology

The above three types of methods all have their own advantages and disadvantages. The interferometric method can obtain the real part and the imaginary part of the complex coherence, but the sampling points are limited, and the more samples are taken, the longer the experimental process takes; the diffraction method experiment and processing process Simple, but involves zero-order approximation, the higher the coherence, the greater the error; the fourth-order correlation method has similar shortcomings to the interferometric method, that is, the experiment takes a long time and does not have the ability to measure in real time

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