Selective two-step photoionization of F-aggregate centers using 1.06-microm radiation.
A two-step photoionization of several potentially laser-active F-aggregate centers is observed in additively colored crystals by using high-intensity 1.06-microm pulses from a Q-switched Nd:YAG laser. The centers produced include the lithium (F(2)(+))(A) center in KI, which has lased with tunability from 2.4 to 4.0 microm, and N(1) (+) centers in KBr, which show promise of lasing. Steady-state concentrations of ionized (F(2)(+))(A) and N(1) (+) centers are found to be considerably larger than those produced by using blue or near-ultraviolet excitation.
Schneider
I
I
Foster
D R
DR