Change in Luminescent Properties of Diamond Stimulated by Subnanosecond Laser Pulses at Low Temperatures

The effect of 532-nm pulsed laser radiation on properties of a single-crystal diamond film containing optically active SiV^‒ centers is studied using in-situ measurements of the photoluminescence spectra at a temperature of 77 K. It is shown that at a pulse duration of 500 ns, the threshold energy density at which the rearrangement of SiV^‒ centers is recorded is ~0.112 J/cm². The rearrangement leads to a decrease in the intensity of the zero-phonon emission line of SiV^‒ centers relative to the intensity of the Raman scattering signal on optical phonons of the diamond matrix. With an increase in the energy density of incident pulses to 0.540 J/cm², the luminescence quenching effect reaches saturation, and traces of ablation and/or graphitization are observed on the film surface. The found effects are explained by local heating of the diamond film due to the processes of three-photon absorption of light, in which the absorption coefficient sharply depends on the energy of incident pulses.