Broadband and fine-structured luminescence in diamond facilitated by femtosecond laser driven electron impact and injection of "vacancy-interstitial" pairs

Opt Lett. 2021 Mar 15;46(6):1438-1441. doi: 10.1364/OL.414583.

Abstract

Ultrafast heating of photoionized free electrons by high-numerical-aperture (0.25-0.65) focused visible-range ultrashort laser pulses provides their resonant impact trapping into intra-gap electronic states of point defect centers in a natural IaA/B diamond with a high concentration of poorly aggregated nitrogen impurity atoms. This excites fine-structured, broadband (UV-near-infrared) polychromatic luminescence of the centers over the entire bandgap. The observed luminescence spectra revealed substitutional nitrogen interaction with non-equilibrium intrinsic carbon vacancies, produced simultaneously as Frenkel "vacancy-interstitial" pairs during the laser exposure.