Illustration of the Coherence of Non-stationary Optical Field Sthrough a Two Beam Interference Experiment

The interference phenomenon in non-stationary optical fields is investigated. We present a method of describing the interference of partially coherent optical beams by using only observable quantities, expressed entirely as temporal averages of the instantaneous signals, which better relates the experimental observations to the coherence properties of the field. We show that this method of description allows, even through a simple experimental method, to obtain a quantitative measure of the degree of optical coherence. In order to do so, we simulate the results of an interference experiment in which the optical field is non-stationary, recorded by means of the revolving disk method. In our analysis, we take into consideration all the aspects of the detection process, including the sensitivity of the photographic film upon which the intensity of the optical field is recorded. Graphical representations of the simulated experimental results are presented for all relevant cases.