Adjusting the nonlinear absorption of a CdTe thin film under electron beam irradiation

Abstract The morphological characterization and the measurements of the nonlinear absorption of CdTe thin films using 1030 nm and 515 nm, 200 fs pulses are reported. The original film and the film irradiated by an electron beam are analyzed. The original film having 1 at% Cd superstoichiometry demonstrated transformation of nonlinear absorption from two-photon absorption to the competition of the latter process and saturable absorption under the variation of 1030 nm pulse energy. The film irradiated at 1015 electrons/cm² fluency of electron beam did not show the saturable absorption while demonstrating the enhanced two-photon absorption. At 515 nm, the saturable absorption in the original film was followed by two-photon absorption, while the irradiated films demonstrated the enhanced saturable absorption. The modifications of absorbance, energy states, and XRD of the CdTe film irradiated by electron beam, resulting in the enhancement of the nonlinear absorption at different wavelengths of the probe pulses are discussed.

Hali tarjima qilinmagan