The study of criterion from Fresnel diffraction to Fraunhofer diffraction

In optics,the distinction between Fresnel diffraction and Fraunhofer diffraction is not only a fundamental but also a significant problem.However,the criterion,which is founded on the transition from near-field diffraction to far-field diffraction,is discussed by experiment,or by numerical calculation and analog simulation.Based on the theory of scalar diffraction and the mathematical analysis,the paper gives the criterion(the value of the Fresnel number,F=0.203),and finally comes to the conclusion in accord with the above-mentioned papers(F=0.223).