Page 30 - High Power Laser Handbook

ChAPTER 1

Carbon Dioxide Lasers

Jochen Deile
Manager, Laser Development, TRUMPF Inc.,
Farmington, Connecticut

Francisco J. Villarreal
Chief Laser Scientist, TRUMPF Inc., Farmington, Connecticut

1.1 Introduction
The carbon dioxide (CO ) laser has been studied intensively over the
2
past several decades. Although no longer being studied by academia,
these lasers are still the most utilized in industrial applications, in
terms of both units and dollars. Typical applications include metal
cutting and welding; processing of nonmetals, such as plastics, fabric,
and glass; and marking and coding applications—as well as many
medical, dental, and scientific applications. Overall, laser cutting
makes up approximately 25 percent of all industrial laser applica-
tions, which totaled about US$6 billion annually worldwide in 2008.
CO lasers have been successful because they are so versatile; a CO
2
2
laser can process almost any material of almost any thickness.
Historically, CO lasers have been able to produce more power,
2
with higher beam quality, and at lower costs than other lasers. Multi
kilowatt CO lasers have been available since the early 1980s. One of
2
the major breakthroughs for the CO laser came with the improved
2
excitation of the CO molecule by the addition of nitrogen (N ) to the
2
2
laser gas. Technological advances reduced the size of the laser and
1
made it absolutely reliable in industrial environments. Another
major breakthrough in terms of reliability was the introduction of
radio frequency (rf)–excited designs. Although fiber beam delivery
systems are not available for CO lasers and even though other tech-
2
nologies now offer better efficiencies, CO lasers will be around for a
2
3