Product Code: ICAL07_505

Diode Laser Pump Sources for Advanced Solid-State Lasers
Authors:
Friedhelm Dorsch, Trumpf Photonics; Cranbury NJ USA
John Hostetler, Trumpf Photonics; Cranbury NJ USA
Ulrich Bonna, Trumpf Photonics; Cranbury NJ USA
Greg Charache, Trumpf Photonics; Cranbury NJ USA
Ching-Long Jiang, Trumpf Photonics; Cranbury NJ USA
Carl Miester, Trumpf Photonics; Cranbury NJ USA
Viorel Negoita, Trumpf Photonics; Cranbury NJ USA
Robert Roff, Trumpf Photonics; Cranbury NJ USA
Werner Uhlenberg, Trumpf Laser GmbH; Schramberg Germany
Nicholas Usechak, Trumpf Photonics; Cranbury NJ USA
Thilo Vethake, Trumpf Photonics; Cranbury NJ USA
Presented at ICALEO 2007

All advanced solid state lasers, independent of their active material geometry rod, thin disk and fiber require matched pump sources to fully allow improved performance. In particular, the laser source brightness is of high importance for many industrial applications: in many cases, higher output power and better focusability allow faster processes. Present advance SSL cannot be pumped by diode laser radiation as it is emitted by the semiconductor chip, but require appropriate beam shaping to match the pump light cross section and divergence to the active material volume. E.g. for rod lasers pump light volume and SSL mode volume in the active material should overlap to a high degree, for fiber lasers the pump light must be launched into the pump core of the active fiber and for thin disk lasers the pump spot size on the disk must be adjusted to the mode dimension at the disk location. Industrial applications require very over all uptimes, i.e. high reliability on the system level. In most cases, the pump source consist of various (up to many) individual diode lasers that are combine in sometimes very complex modules. The entire pump source must fulfill the reliability requirements, which is more demanding than the statistically expected reliability of one its individual element.
For very high power lasers about 1 kW average output power - the pump source is a significant part of the system costs. The price of the pump sources must be kept low. This not only refers to the investment cost, but also to the costs over the whole useful time: The pump source must show long lifetime in the range of tens of thousands of hours. The various requirements high brightness, high reliability and long life time, and low costs conflict and the laser systems designer as to find the optimum compromise. A close cooperation between diode laser pump source development and SSL design in an vertically integrated company is essential to realize the optimum.