Lothar Ackermann

407 W End-pumped Multi-segmented Nd:YAG Laser

A composite crystalline Nd:YAG rod consisting of 5 segments with different dopant concentrations for high power diode end-pumping is presented. A maximum laser output power of 407 W with an optical-to-optical efficiency of 54 % was achieved by longitudinal pumping with a high power laser diode stack.

Characterization and laser performance of a new material: 2 at. % Nd:YAG grown by the Czochralski method

We report on the optical quality and laser performance of Czochralski-grown 2-at. %-doped Nd:YAG. Using a diode pumped laser in an end pumped configuration, we compare the laser performance of this material with the performance of 1-at. %-doped Nd:YAG and 0.7-at. %-doped Nd:YVO4 crystals. Experimental results show the superior performance of 2-at. % Nd:YAG over Nd:YVO4. With a pump power of 25.7 W, a maximum output power of 12.3 W with a slope efficiency of 57% and an optical-to-optical efficiency of 48% were achieved.

First Yb:NaGd(WO4)2 Solid-State Laser Pumped by Ti:Sapphire and Diode Laser

Room and low temperature spectroscopy of Yb:NaGd(WO4)2 is presented. Laser operation near 1030 nm is demonstrated under Ti:sapphire and diode laser pumping at 975 nm with maximum slope efficiencies of 36% and 19%, respectively.

Power scaling of diode end-pumped Nd:YAG lasers by hyperbolic dopant concentration profiles

A method for scaling end-pumped rod lasers to high output powers by employing a crystal with a hyperbolic dopant concentration profile is presented. An output power of 187 W with 53% optical-to-optical efficiency has been demonstrated.

High-Power End-Pumped Multi-Segmented Nd:YAG Laser

A diode end-pumped composite Nd:YAG laser consisting of up to 5 segments with different dopant concentrations is presented. An output power of 137W was achieved with 52% optical to optical efficiency.

High-Power Multi-Segmented End-Pumped Nd:YAG Laser

The first results on power scaling of end-pumped Nd:YAG lasers by applying a multi-segmented-rod will be presented. A maximum laser output power of 407 W with an optical-to-optical efficiency of 54 % was demonstrated.

End-Pumped Nd:YAG Laser Applying a Novel Laser Crystal with Longitudinal Hyperbolic Dopant Distribution

An end-pumped Nd:YAG rod laser design with a longitudinal hyperbolic dopant distribution is presented and 77 W of output power are demonstated. Numerical calculations indicate a homogenization of the longitudinal temperature profile.