Spectroscopy of Ti3+:α-Al2O3

Optical spectroscopy (including laser) of the laser system Ti3+:α-Al2O3 in a temperature range from 5 to 300 K is reported, with the first observation of the zero-phonon absorption on line between 2T2 and 2E levels at 6166 Å, followed by a series of vibronic lines with an average splitting of 194 cm-1. The uv region of absorption is also investigated. Pumping with the 4th harmonic of a YAG:Nd laser excites a blue luminescence with a long-lived (∼ 35 μs) and a weak short-lived component; it excites also the known red luminescence. Characteristics and possible mechanisms for these luminescence features are discussed.