Page 332 - High Power Laser Handbook

CHAPTER 12

Ultrafast Solid-State

Lasers

Sterling Backus
Vice President, Research and Development, Kapteyn-Murnane
Laboratories, Inc., Boulder, Colorado

12.1 Introduction
Over the past 15 years, ultrafast laser technology and its applications
have progressed by leaps and bounds, ever since the widespread
introduction of solid-state ultrafast laser materials in the early 1990s.
1
In 1990, the state-of-the-art femtosecond (fs) laser used dye laser
media and could generate output powers in the tens of milliwatt
(mW) range, with pulse durations of ~100 fs. The successful applica-
tion of titanium-doped sapphire (Ti:sapphire) to ultrafast lasers
immediately resulted in an order of magnitude increase in average
power (to ~1 W), as well as in the ability to easily and reliably gener-
2
ate pulses of less than 10 fs. This technological advance has since led
to a tremendous broadening of the field of ultrafast science, and more
applications could be successfully implemented with the new gener-
ation of lasers. For example, the use of ultrafast lasers for machining
and materials ablation began in the mid-1980s, with the realization
that the high-intensity laser–matter interaction is fundamentally dif-
ferent on femtosecond (compared with picosecond or nanosecond)
timescales, allowing for a much more precise and well-controlled
3
ablation. Peak powers into the petawatt (PW) regime have been real-
4–6
ized, owing to ultrafast pulses. This high-peak-power capability
has also defined many other applications throughout physics, chem-
istry, and biology. However, the “real world” applications of femto-
second lasers only became practical with the development of
high-power solid-state (predominantly Ti:sapphire) lasers. Femtosec-
ond lasers are now used in a few industrial and medical settings, such

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