Recovery of Properties of a Material from Transfer Function of a Bulk Sample (Theory)

Properties (absorption, gain) of a medium are supposed to be functions of the intensity of light. For the straightforward characterization at a given intensity, either the physical model should be used (to extract from the measurements only the parameters of the model), or the sample should be thin, that allows to neglect variation of intensity within the example. The measurement of the transfer function of the bulk sample is suggested as an alternative. The transfer function of a sample determines the output intensity in terms of the input intensity. For the given transfer function, the distribution of intensity within the sample appears as the superfunction. Method for the recovery of the superfunction from the transfer function is suggested.