Degree of spectral coherence, space–frequency plots and correlation-induced spectral changes

Abstract

In this work we experimentally investigate some aspects of spectral coherence using a powerful acquisition and processing method based on an intensified CCD-camera. We obtain an accurate and fast measurement of the degree of spectral coherence μ 12( ν) for a thermal light source as a function of frequency. We also present 3-D plots of the function: 1+Re{ μ 12( ν)exp(−2πi νΔτ)} vs. position and frequency; these graphs provide the simplest visual interpretation of correlation-induced spectral changes.