Subject of study. Several characterization methods that utilize recording and reading out of dynamic gratings to analyze functional materials are proposed. Method. The methods are based on pulsed recording of thin and volume dynamic gratings followed by reconstruction using continuous laser emission to facilitate the detection of the formation and relaxation dynamics of the recorded diffraction grating. Nonlinear optical, thermo-optic, and kinetic properties of condensed media were obtained based on the measured kinetics of the diffracted signals. Main results. The performance characteristics of a dynamic grating method were analyzed for characterization and parameter measurements of functional materials. In particular, the efficacy of the measurement of the kinetic properties for pulsed recordings of thin and volume holographic gratings was demonstrated. The lifetimes of the short- and long-lived trap levels involved in recording of the dynamic grating were determined in a photorefractive bismuth silicate crystal and the dependence of the diffraction efficiency of the gratings on the intensity of the recording radiation was determined. The advantages of using an additional grating (homodyne) to enable the separation of the contributions of different simultaneously manifesting nonlinearity mechanisms were demonstrated. This method was applied to monocrystalline germanium. A method for assessing the thickness of a film on the surface of a sample based on the amplitude of an oscillating component related to a sound wave propagating in air in the vicinity of the film's surface was also proposed. A silicon dioxide film was considered as an example. The application of the diffraction to different orders on volume dynamic gratings was proposed for the measurement of the nonlinear optical susceptibility of the fifth and higher orders. The proposed approach was evaluated on photorefractive crystals and semiconductor media. The kinetic and thermo-optic properties, including the time of the population of trap levels, thermo-optic coefficient, and thermal diffusivity, of the media were determined. Practical significance. The proposed characterization methods facilitate the isolation of different nonlinearity mechanisms involved in the formation of dynamic gratings and the measurement of nonlinear optical, thermo-optic, and kinetic properties (optical susceptibilities of different orders, thermo-optic coefficient, thermal diffusivity, and lifetimes of free-charge carriers and trap levels). (C) 2022 Optica Publishing Group
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