Comparative study of tunable room-temperature laser operation in the 908-1100-nm range: LiF : F-2(+) and Ti3+: sapphire

We report on a comparative evaluation of efficient room-temperature solid-s tate lasers based on Ti: sapphire and LiF:F-2(+) operating in the 900-1100- nm range. LiF:F-2(+) lasers are shown to operate with substantially lower t hreshold, broader tuning, and higher output pulse energies. The shorter flu orescence lifetime in LiF:F-2(+) leads to higher peak output powers and a c onsiderable reduction in buildup-time fluctuations. The main limitations on LiF:F-2(+) laser operation are identified as amplified spontaneous emissio n (ASE) and long-term thermal degradation of the color centers. ASE restric ts the tuning range, slope efficiency, and bandwidth of the LiF:F-2(+) lase r for high pump intensity, but broader tuning is achieved with longer pump pulses. The beam quality of the LiF:F-2(+) laser is comparable with that of the Ti:sapphire laser. (C) 2000 Optical Society of America OCIS codes: 140 .1700, 140.3380, 140.3590, 010.3640, 140.3070, 140.3580, 140.3600.