Long-lived transient gratings excited by UV laser radiation in the absorption band of synthetic diamond crystals have been observed for the first time. Decay constants of the gratings depend on the crystal defects nature and lie in the range of 0.1-100 ms that is 10³-10⁴ larger than that of thermal gratings. They are observed as slow tails of the scans which describe the time evolution of the signal diffracted by the laser induced grating in the crystal. Electron-paramagnetic- resonance shows a correlation between the EPR signal and long-lived grating amplitude. The defects with unpaired electrons are mainly responsible for the gratings observed. Selectivity of the long-lived gratings to the wavelength of excitation is shown. The gratings reveal a strong sensitivity to the crystal temperature. For example, the grating lifetime decreases by several orders of magnitude when the crystal temperature increases from 20 degree(s)C to 200 degree(s)C. It proves the defect nature of the gratings observed. Light-induced grating approach appears to be a sensitive tool for the investigation of defects in diamond crystals including those that do not yield the luminescence.

Date Published: 15 March 2001
PDF: 5 pages
Proc. SPIE 4358, Optics of Crystals, (15 March 2001); doi: 10.1117/12.418847

Published in SPIE Proceedings Vol. 4358:
Optics of Crystals
Vasiliy V. Shepelevich; N. N. Egorov, Editor(s)