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The design and performance of a short-pulse (1.5 ns), high-energy (90 mJ/pulse) nonlinear cavity-dumped, frequency-doubled, solid-state intracavity Raman laser is presented. The laser described is utilized as the transmitter in a high-resolution surf-zone marine imaging lidar system.

A diode side-pumped Cr:LiSAF laser has been demonstrated with a 30 mJ normal mode output energy, and an optical to optical eficiency of 17%. Improved optical quality laser material has been grown with several Cr concentrations. Optimum Cr concentration has been calculated and experimentally confirmed.

The interest in diode pumped solid state lasers in the 2 μm region in recent years has been well documented. The need for compact, highly efficient sources has led to the study of new laser hosts which may improve performance. We have grown and analyzed the spectroscopic properties of two Tm3+-doped silicate oxyapatite hosts and one orthosilicate. These hosts are CaY4(SiO4)3O [CaYSOAP], CaLa4(SiO4)3O [CaLaSOAP], and Y2SiO5 [YSO or YOS]. The spectroscopic properties of these new hosts are compared with those of Tm3+:YAG, and indicate that these hosts may offer improvements to Tm3+:YAG in increasing tunability in the 2 μm region and in improving laser performance for the 2.3 μm transition. Preliminary laser results of a Tm:CaYSOAP laser are also presented.

We have studied the characteristics of Thulium and Holmium/Thulium YAG lasers using high power laser diode pumping. Measurements of laser performance have been combined with spectroscopic measurements and compared to rate equation models for these materials.

We report on the growth and characterization of SrGdGa307, La3Ga5Si014 and La3Ga5GeO14 doped with Nd and Tm as candidate crystals for improved diode pumped lasers.

Trivalent uranium-doped LiYF4, crystals have been grown and evaluated as potential diodepumped lasers. Strong fluorescence in the range of 2.1 - 2.6 μm has been measured with a 170 μs lif e time.

We have evaluated the laser performance of flashpumped Cr;Tm -aluminum and scandium garnets and have demonstrated broad tunability from 1.94 μm to 2.09 μm with TEM00 mode output energies exceeding 1 J.

Operation of an efficient room temperature, flashlamp-pumped Cr;Tm:Y3A15O12 (YAG) laser at 2.014 μm is reported with a 43 J threshold, 2 J output energy, and 4.5% slope efficiency. Room temperature, flashlamp-pumped laser action is also demonstrated for the first time in a similar host, Y3Sc2Ga3O12 (YSGG) codoped with Cr and Tm. The observed laser wavelength in Cr;Tm:YSGG is measured as 2.010 μm.

Studies of Cr to Tm transfer efficiencies have led to the optimization of dopant concentrations for a flashlamp-pumped 2.09 μm Cr:Tm:Ho:YAG laser. We report slope efficiencies of >5.0% with thresholds below 28 J.