Longitudinal Coherence Of Partially Coherent Radiation

In1950s, Hanbury Brown and Twiss conducted a series of second-order strengthrelated experiments--the famous HBT experiment, with the purpose of diametermeasuring of fixed stars. Later people gradually found out that using coincidencemeasurement methods in optics is the real meaning of the experiment, which canexplore light field second-order (high-order) related properties experimentally.To1990s, the realization of light quantum entanglement imaging and quantuminterference experiment which based on coincidence measurement methods arousedpeople’s research enthusiasm to the related properties of incoherent light source andsuch representative light sources. At the beginning of the century, based on thesuccess of incoherent light source strength association imaging and interferenceexperiment, people began to debate on whether incoherent light source second-orderrelated properties is classic effect or quantum effect as well as its potential applicationvalue in different fields.This thesis mainly research in the field of third-order longitudinal coherencestudy to partially coherent light. First, make theoretic derivation and numericalsimulation to third–order longitudinal correlation function of completely coherentlight and partially coherent radiation by the use of correlation function properties andoptical transmission properties in quantum optics and Fourier optics. Throughtheoretic derivation and numerical simulation.We discovered that partially coherent radiation longitudinal coherencethird-order longitudinal contrast ratio theoretically maximum value can reach1/2which is bigger than second-order longitudinal contrast ratio’s theoretically maximumvalue1/3. This result proved that with the increase of orders the longitudinalcoherence of partially coherent radiation field increase too. Based on this theoreticalresearch, we use synchronous scanning and asynchronous scanning to analysepartially coherent radiation third-order longitudinal coherence and discovered that contrast ratio of asynchronous scanning is higher than that of synchronous scanning;we can also analyse from the resulting numerical simulation image thatdistinguishability from asynchronous scanning is lower than that of synchronousscanning. Through the analysis to light source surface during the whole theoreticalresearch we can see that with the increase of light source transverse area, the visibilitybecome more clearer; on the contrary, the visibility become weaker with the increaseof light source size transverse coherent width.