Calculation and verification of optical diffraction performance of random metallic meshes

In this paper, the optical diffraction performance calculation method of random metallic meshes based on the secondary wavelet source far-field coherent superposition is proposed. First, the random mesh pattern to be calculated is processed into a two-dimensional matrix with binary data (0/1). The final diffraction result can be obtained by summing the amplitude distribution of the diffracted light from the binary data 1 (blank region) and 0 (metal line region) in the sample region based on the secondary wave source superposition method. To verify the validity of the calculation, a random metal mesh sample was tested using the crack template method. The calculation results show that the maximum amplitude of the sample's high-order diffraction distribution normalized intensity is −27.5 dB. In comparison, the measured result is −28.2 dB, which is in good agreement with the calculation result. Since it is no longer limited to the periodic regular network structure, the calculation result of optical diffraction performance is greatly simplified. The optical diffraction performance calculation method proposed in this paper is applicable to various network structures, especially for random network structures, whose optical diffraction performance can be obtained without measurement processing. It will effectively promote the research on the optical diffraction performance of random metallic meshes.