Page 256 - High Power Laser Handbook

CHAPTER 10

Thin-Disc Lasers

Adolf Giesen
Head, Institute of Technical Physics, German Aerospace Center
(DLR), Stuttgart, Germany

Jochen Speiser
Head, Solid State Lasers & Nonlinear Optics, Institute of
Technical Physics, German Aerospace Center (DLR),
Stuttgart, Germany

10.1 Introduction
Thin-disc lasers are diode-pumped, solid-state lasers scalable to very
high output power and energy with very high wall-plug efficiency
and good beam quality. These design properties have been demon-
strated during the past decade, and therefore, many companies are
offering thin-disc lasers for various applications ranging from lasers
for eye surgery and other medical applications to metal cutting and
welding applications, with output powers up to 16 kW. This chapter
reviews the results for continuous wave (CW) operation and for
pulsed operation with pulse durations ranging from 100 femtosec-
onds (fs) to several ms. In addition, the scaling laws are discussed,
showing that the physical limits for CW and pulsed operation of thin-
disc lasers are far beyond the state of the art today.
10.2 History

Since the late 1980s many groups have worked on diode-pumped sol-
id-state lasers, replacing the lamps for pumping with laser diodes. One
goal of this work was to increase the wall-plug efficiency of the laser
systems; another was to improve the beam quality of such lasers.
Nearly all groups worked on the classical rod or slab design. However,
some groups studied the properties of other laser active materials that
could not be pumped using ordinary lamps. 1,2

225