Hermann Voelckel

Reliability of high-power diode laser bars in industrial applications

The successful use of high power diode lasers (HDL), which are based on 1 cm semiconductor bars, is critically linked to the optimization of output power, beam quality, reliability, and cost. Even though some criteria can be improved only on the costs of others, the common point of concern is the reliability. A defined reliability allows the user to estimate not only the investment costs but also all service and replacement costs. All those economical concerns can be translated into technical requirements. All efforts to fulfill these technical requirements are part of JENOPTIK Laserdiode’s LongLifeTechnology.

Near-diffraction-limited diode-pumped thin-disk Nd:YVO 4 laser

Room temperature operation of a Nd:YVO4 thin disk laser with excellent beam quality is reported. Pumping by a fiber coupled diode laser with 10 W at the fiber end yields a continuous wave output power of 4.4 W at 1064 nm. The corresponding total optical efficiency is 44% and the average slope efficiency is 46%. For higher pump powers, a maximum output power of 13.7 W was achieved in a near diffraction limited beam.

High-power cw diode-pumped Nd:YAG rod lasers for industrial applications

The use of a cw diode-pumped Nd:YAG rod laser for industrial applications is investigated. The laser is pumped by water cooled high-power laser diode bars in a star-shaped transverse pumping configuration. An output power of 75 W is achieved with 240 W of pumping power, corresponding to 40% slope efficiency. Thermal lensing and birefringence of a laser rod with a diameter of 4 mm is investigated. High fundamental transverse mode and second harmonic efficiency is reported. A simple scalable concept for lasers with 10 W to 100 W output power is presented.