Page 292 - High Power Laser Handbook

260 So l i d - S t at e La s e r s Thin-Disc Lasers 261

multipass with 12 double passes through the disc, achieving an
amplification of 4 to 6, depending on the starting pulse energy. The
system delivers up to 48 mJ with a maximum delay of 400 ns after
an electronic trigger signal.
68
A similar geometrical multipass amplifier is used in a high energy
CPA thin-disc system actually under development. The goal is to pro-
duce a pulse energy of about 1 J with a repetition rate of 100 Hz and a
pulse duration of less than 5 ps. Actually, pulses stretched to 2 ns were
amplified by a combination of a regenerative thin-disc amplifier and a
multipass thin-disc amplifier to a pulse energy of 320 mJ; the compress-
ibility to ~ 2 ps was demonstrated with pulse energies of ~180 mJ. 69
From these results it can be seen that the thin-disc laser design is
able to generate and amplify pulses up to high energies for all pulse
durations between femtoseconds and nanoseconds.

10.8 Industrial Realizations

To date, 20 licenses of the thin-disc laser design have been sold to
companies worldwide. Some of these companies already offer thin-
disc lasers on the market.
Rofin-Sinar Laser GmbH offers materials processing lasers with
output powers from 750 W to 4 kW; these lasers are coupled into an
optical fiber with 200 mm core diameter (numerical aperture
[N.A.] = 0.2). Trumpf Laser GmbH + Co KG offers thin-disc lasers
from 250 W to 16 kW output power, which are also coupled into fibers
with 200-mm core diameter. Because of the good beam quality of these
lasers (comparable to that of CO lasers in the same power range),
2
these lasers are excellent for high power materials processing.
Jenoptik Laser, Optik, Systeme GmbH is selling high-power thin-
disc lasers in the green, red, and blue spectral range (up to 8 W green,
0.8 W blue, and 2 W red). It is also selling q-switched thin-disc lasers
with up to 40 W for marking and drilling.
These examples show that the thin-disc laser has successfully
found its way from the laboratory to real applications in industry.
More companies will enter the market within the next few years.

10.9 Summary

All the results in this chapter show the potential of the thin-disc laser
design for high power lasers that are easy to build and operate. In
particular, the simple scaling laws of the thin-disc laser design and
the easy adaptation to many laser active materials will support the
implementation of the thin-disc laser design to available industrial
laser systems.
The thin-disc laser is an innovative laser concept that allows to
build diode-pumped solid-state lasers with highest output powers,