We studied the structure of absorption domains in cadmium sulfide by the following experimental techniques: the domains luminescence spectra; the transmission of a probe beam through the domain in the direction perpendicular to that of domain motion; and the radial distribution of intensity of the excitation light transmitted through the domain. The absorption domains in cadmium sulfide are found to be relaxation waves with final state in the Urbach absorption tail, their structure being analogous to that of burning waves studied in the kinetics of chemical reaction. The self-organization in this effect results in a weak dependence of the maximum domain temperature on excitation conditions. A blue shift of the luminescence line has been found for running domains with light intensity increasing.
V. A. Stadnik, V. A. Stadnik,
"Structure of absorption autowaves (domains) in cadmium sulfide", Proc. SPIE 1840, Transverse Patterns in Nonlinear Optics, (16 December 1992); doi: 10.1117/12.131803; https://doi.org/10.1117/12.131803