Effect of the Delay of Thermal Emission Fronts upon Pulsed Laser–Thermal Excitation of Er₂O₃ and Ruby

The spectra and kinetics of selective and continuum thermodynamically equilibrium emission of electromagnetic radiation from Er₂O₃ microcrystals and a ruby single crystal in the visible and near-IR spectral regions under laser–thermal excitation by electric-discharge CO₂ lasers at a wavelength λ = 10.6 µm in the cw and pulsed modes have been experimentally investigated. The effect of the delay of continuum emission fronts and intensity peaks relative to laser pulses is explained by the difference in the temperatures of the heated layer and electromagnetic radiation. The delay time of the electromagnetic emission maximum is the characteristic time for establishing thermal equilibrium.