Actively Q switched radially polarized Ho:YAG laser with an intra-cavity laser-written S-waveplate.

Nanosecond Q switched pulses and radial polarization are established stand-alone techniques for enhanced laser materials processing applications, but are generally challenging to achieve simultaneously at high average power levels. Here, we demonstrate a 20.6 W radially polarized Ho:YAG rod laser which has been actively Q switched in order to generate 515 J, 210 ns pulses at 2097 nm.

Controllable duration and repetition-rate picosecond pulses from a high-average-power OP-GaAs OPO.

We report an orientation-patterned gallium arsenide (OP-GaAs) optical parametric oscillator (OPO) offering a high degree of temporal flexibility with controllable pulse repetition rates from 100 MHz to 1 GHz and pulse durations from ∼95 ps to ∼1.1 ns. The maximum average power of 9.

Nested-ring doping for highly efficient 1907 nm short-wavelength cladding-pumped thulium fiber lasers.

Cladding-pumped Tm-doped fiber lasers operating below 1950 nm have difficulty matching the high-efficiency, power-scalable output that can be achieved at longer wavelengths. This challenge arises due to the strong three-level behavior at short wavelengths and strong competition from higher-gain long wavelength emission. In this Letter, we demonstrate a nested-ring fiber design in which a highly doped Tm ring is embedded within a larger undoped core.

High-average-power picosecond mid-infrared OP-GaAs OPO.

We report a high-average-power mid-infrared picosecond (ps) optical parametric oscillator (OPO) based on orientation-patterned gallium arsenide (OP-GaAs), with wide wavelength tunability. The OP-GaAs OPO is synchronously pumped by a thulium-doped-fiber (TDF) master oscillator power amplifier (MOPA), seeded by a gain-switched laser diode. At a pump power of 35.

47 W continuous-wave 1726 nm thulium fiber laser core-pumped by an erbium fiber laser.

The high-power, short-wavelength operation of a thulium-doped silica fiber laser at 1726 nm has been demonstrated in a core-pumped monolithic (all-fiber) resonator configuration, in-band pumped by a high-power erbium-only fiber laser operating at 1580 nm. The thulium fiber laser yielded 47 W in a single-spatial-mode output beam for 60-W absorbed pump power. The corresponding slope efficiency, with respect to an absorbed pump power of 80%, compares favorably with the theoretical maximum (Stokes) efficiency of 91.