Quasi-monochromatic Field In The Interaction Strength Of Optical Fractional Fourier Transform

Since the Fractional Fourier Transform was first introduced intooptics, and was presented its physical interpretation and the basicmode of optical realization by Mendlovi and Ozaktas and others in1993, Fractional Fourier Transform，as a new mathematical methodand a means of the research into unsteady-state information, hasbecome an extremely effective mathematical tool in the imageencryption, neural network, spatial filtering, lens design, opticalmeasurement and so on. In 2004, Fractional Fourier Transform wasapplied to the research into the partially coherent light field,followed by its wide use. However, the completely detailedcoverage of its study in the partially coherent imaging system fieldhas not been seen.This paper describes an overview of the basic physicalquantities of the partially coherent field, and the link betweendifferent physical quantities . And based on the Huygens - Fresnelprinciple, the quasi-monochromatic field mutual coherence function and the mutual intensity of the transmission formula are deduced.Secondly, on the basis of the quasi-monochromatic field mutualintensity propagation theory and with the aid of the implementationpattern of single-lens Fractional Fourier Transform proposed byLohmann , the mutual intensity of Fractional Fourier Transform isachieved. And in the two extreme cases , that is in the completelycoherent light radiation field, mutual intensity Fractional FourierTransform is reduced to the complex amplitude Fractional FourierTransform . In a completely non-coherent light radiation field, whenthe line length of light source itself and that of the viewing area aremuch smaller than the distance between them, the complex degreeof coherence in the viewing area can be normalized through thelight intensity distribution. The reliability and feasibility of theconclusion are tested through computer simulations and thisconclusion has practical value for the research into the partiallycoherent field imaging system, optical information transmission,information processing and other application areas.