A Computational Model for the Far-field Light Intensity of a Lens

This paper focus on the problem of spatial distribution mismatch caused by direct discrete Fourier transform of near-field light waves, study the calculation method of the focal and defocus plane light intensity of a lens, derive the discrete Fourier transform formula for calculating the focal and defocusing surface light field, and establish a mathematical model. The experiment compares the actual light intensity distribution and the calculated light intensity distribution of the lens focal plane and the defocus plane, and the results showed that the difference between the model light field and the actual light field PV value is less than 0.19, and the rms value is less than 0.007. The experiment proves that the far field computation model used in this paper is accurate and effective.