Analysis of time-dependent optical signals and transfer functions by making use of spectral modulation

Abstract

A modulation — spectral method is used to consider the solution of the phase problem in optics, as applied to the analysis of time-dependent signals and of transfer or instrumental functions describing the optical characteristics of an object under study. In particular, the reported analysis applies to ultrashort signals and processes. A version of simultaneous analysis of the structure of an initial optical signal and the amplitude — phase effect of an object or a medium under study on this signal, which is characterised by additional modulation of radiation, is considered. To obtain the desired information, it is necessary to record the spectral intensity distributions for a signal directly transmitted through an object, a signal subjected to additional spectral modulation and transmitted through an object, and the aforementioned signals with additional time modulation imposed in a certain way. To some extent, modulation should provide visualisation of the phase information.