Optical properties of the In 0(1) center in KCl

Abstract

We report both experimental and theoretical studies of the optical properties in KCl of a defect-associated In center whose sole previously identified optical transition was a strong absorption band peaking at 610 nm. With the aid of an optical tagging technique, we have been able to identify with that center two new but much weaker absorption bands peaking at 860 and 960 nm, respectively. We show that the energy splittings, relative strengths, and less perfectly, the polarizations of those three transitions make fit to the In 0(1) center model, i.e., the model, initially developed for the Tl 0(1) center, of a neutral atom perturbed by the field of an adjacent anion vacancy. However, in contrast to the Tl 0(1) center, the In 0(1) center lacks a significant emission, excluding its use as a laser gain medium.