Efficient resonantly-clad-pumped laser based on a Er:YAG-core planar waveguide.

We demonstrated continuous wave operation of an in-band pumped Er:YAG planar waveguide laser with the output of 75 W at 1645 nm and a slope efficiency of 64% with respect to the absorbed pump power at 1532 nm.

Resonantly pumped single-mode channel waveguide Er:YAG laser with nearly quantum defect limited efficiency.

We demonstrated the continuous-wave operation of a resonantly pumped Er:YAG single-mode channel waveguide laser with diffraction-limited output and nearly quantum defect limited efficiency. Using a longitudinally core-pumped, nearly square (61.2 µm×61.6 µm) Er3+:YAG waveguide embedded in an undoped YAG cladding, an output power of 9.1 W with a slope efficiency of 92.8% (versus absorbed pump power) has been obtained. To the best of our knowledge, this optical-to-optical efficiency is the highest ever demonstrated for a channel waveguide laser.

Acousto-optically Q-switched, resonantly pumped, Er:YVO4 laser.

We report on the performance of an acousto-optically Q-switched Er:YVO4 laser resonantly pumped in the 4I 15/2 → 4I 13/2 transition. The laser output was π-polarized at 1603 nm. It operated with a 1-40 kHz pulse repetition rate (PRR) and delivered up to 1.15 W of average output power. A slope efficiency of 45% with respect to the absorbed pump power was demonstrated at the pulse repetition rates of 10 kHz and above. The best Q-switched operation with 470 µJ, 50 ns long pulses was achieved at the PRR of 1-2 kHz and pumping with a fiber-coupled laser diode. This Q-switched pulse energy is the highest reported for Er:YVO4 single crystal laser.

High efficiency, resonantly diode pumped, double-clad, Er:YAG-core, waveguide laser.

We report on the highly efficient, resonantly diode-pumped Er:YAG-core, double-clad, all-crystalline eye-safe waveguide laser. A 500 × 500 µm Er(3+)(1%):YAG single-crystalline core with an ultra low numerical aperture (NA) of ~0.02 was surrounded by a 700 × 700 µm undoped single-crystalline YAG cladding. The entire Er:YAG/YAG core/clad structure was over-clad by transparent magnesium aluminum spinel (MgAl(2)O(4)) ceramic. The waveguide was continuously (CW) clad-pumped by a spectrally-narrowed, fiber-coupled InGaAsP/InP laser diode module at ~1532 nm. We achieved 25.4 W of output power at 1645 nm with a beam quality of M2 ~2.6. The achieved 56.6% slope efficiency with respect to the absorbed pump was derived by factoring out scattering loss of the pump light in the inner cladding. With a wavelength-selective cavity, the waveguide laser delivered ~8 W of output power at 1616.6 nm. To the best of our knowledge, it is the first reported laser experiment with a crystalline Er(3+):YAG-core and a truly double-clad crystalline waveguide structure.

Efficient, resonantly pumped, room-temperature Er3+:GdVO4 laser.

We report an efficient room-temperature operation of a resonantly pumped Er3+:GdVO4 laser at 1598.5 nm. The maximum continuous wave (CW) output power of 3.5 W with slope efficiency of 56% was achieved with resonant pumping by an Er-fiber laser at 1538.6 nm. With pumping by a commercial laser diode bar stack, a quasi-CW (QCW) output of 7.7 W and maximum slope efficiency of ~53% versus absorbed pump power were obtained. This is believed to be the first resonantly (in-band) pumped, room-temperature Er3+:GdVO4 laser.

Spectroscopic properties and laser performance of resonantly-pumped cryo-cooled Er³âº:GdVO4.

We report a highly efficient cryo-cooled eye-safe laser operation of a resonantly-pumped (in-band) Er³âº:GdVO4 single crystal. The maximum continuous wave (CW) power of 10.3 W with 84% slope efficiency was achieved at 1598.7 with pumping at 1538.6 nm by a spectrally-narrowed Er-fiber laser. Under the 1529 nm resonant pumping by a commercially available diode bar stack operating in a quasi-CW (QCW) mode, the laser delivered 37 W of output power with 68% slope efficiency. This is believed to be the first reported cryo-cooled Er³âº:GdVO4 laser, resonantly-pumped into the 4I15/2 →4I13/2 transition.

Spectroscopic characterization and laser performance of resonantly diode-pumped Er(3+)-doped disordered NaY(WO4)2.

We report what is believed to be the first resonantly pumped laser operation based on Er(3+)-doped disordered double tungstate single crystal. Efficient laser operation of an Er(3+):NaY(WO(4))(2) laser at ∼1609.6 nm was demonstrated with the naturally wideband, ∼20 nm, InGaAsP/InP laser diode pumping at ∼1501 nm. Laser wavelength tunability of ∼34 nm was also demonstrated based on disorder-broadened emission features of Er(3+):NaY(WO(4))(2) single crystal.

Nearly quantum-defect-limited efficiency, resonantly pumped, Er3+:YVO4 laser at 1593.5 nm.

Nearly quantum-defect-limited laser operation of a resonantly pumped Er(3+):YVO4 at 1593.5 nm is demonstrated. Maximum slope efficiency of ~85% and true CW power of ~13 W at 1593.5 nm were achieved with a beam propagation factor of M2 ~ 1.05. This slope efficiency is, to the best of our knowledge, the highest efficiency ever reported for a crystalline Er-doped laser.

Directly Single-Diode-Pumped Continuous-Wave Yb(3+):YAG Laser Tunable in the 1047-1051-nm Wavelength Range.

We have demonstrated tunability in a wavelength range of 1047-1051 nm, using the lowest pumping power known to us (1.4 W at 972 nm), for a cw single-diode-pumped Yb:YAG laser. The output power was 166 mW in the multimode regime and 73 mW in the fundamental transverse-mode regime. The laser efficiency was 12.8% and 21% with respect to the incident and the absorbed pump powers, respectively. The linewidth of the laser was Dlambda = 0.05-0.07 cm(-1) (1.5-2.1 GHz), which corresponds to two to three longitudinal cavity modes. A theoretical model of the laser has been developed. Experimental results are in good agreement with the theoretical model.