Robin A. Reeder

Low-heat high-power scaling using InGaAs-diode-pumped Yb:YAG lasers

We report to our knowledge the highest to date quasi-CW output power, 600 W and pulse energy, >1 J, for an InGaAs diode-pumped Yb:YAG laser. In separate preliminary results, we have also obtained 225 W of average output power under true CW diode pumping. This performance was obtained using a laser head designed to be part of a master oscillator power amplifier (MOPA) operating at 3 kW. We summarize why the diode-pumped Yb:YAG crystal laser is ideal for scaling to high average powers and the different approaches being pursued. We also report our latest results for side-pumped rod devices.

Efficient Er:YAG laser operating at 1645 and 1617 nm

A 1534-nm fiber laser pumped Er:YAG laser action at room temperature has been demonstrated with high efficiency at two emission wavelengths: 1645 and 1617 nm. Multiwatt continuous-wave power was demonstrated at both wavelengths and active electrooptic Q-switch operation with >90% Q-switch efficiency was achieved at 1645 nm. Etalon tuned wavelength selection showed excellent agreement with theoretical analysis.

High-power Yb:YAG rod oscillators and amplifiers

We report 0.95 kW average output power from a single cw-diode pumped Yb:YAG power oscillator. The 3-mm diameter solid-state laser rod is side pumped by three sets of cw diode arrays each of which has an electrical-to-optical efficiency of up to 50%. Our phase-conjugate master oscillator, power-amp architecture will incorporate this pump cavity as one of the power amplifiers for multi-kW average power, good beam quality laser applications.

High-Power Side-Diode-Pumped Yb:YAG Laser

We report 600 W quasi-cw output power from a side-diode-pumped Yb:YAG rod power oscillator and 225 W average power in preliminary cw diode-pumping experiments.

Broad L-band operation from resonantly pumped Er:YOS laser

Fiber laser pumped Er:YOS laser action near 1600 nm was achieved at room temperature. Etalons and a diffraction grating were used to generate and control broad-band laser action near the 1600 nm emission center. Efficient operation was achieved in a non-optimized laser test bed.