jean charles jacques – sébastien bax – nicolas cortès
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Jean Charles Jacques – Sébastien Bax – Nicolas Cortès
07/01/2008
CO2 Lasers
Theory & Conception
Contents
CO2 Lasers Theory
11
2
Introduction
3
1
5
Low power CO2 lasers
High power CO2 lasers
Conclusion
4
5
Introduction1
2
10.6 µm in the Infrared wavelengths
Continuous power capability
High efficiency
Power from some tens of W to few tens of KW
3
2
hvk )21(Ev
BhcJJ )1(Ej
Vibration levels; Energy Storage
Bending mode
Symmetric Stretching mode
Asymmetric Stretching mode
Vibrational energy:
Rotational energy:
CO2 Lasers Theory
4
2 CO2 Lasers Theory
Transfer collision
E=2meV<25meV
Active medium compositionCO2: 10-20%
N2: 10-20%
He: 60-80%
Low power CO2 Laser3
5
Sealed CO2 Laser
Regeneration of CO into CO2
Infrared specific optic
Brewster angled windows
DC Discharge
Low power output
Small size for a CO2 laser
No heavy cost and maintenance
Low power CO2 Laser3
6
Waveguide CO2 Laser
Very small BeO waveguide
High pressure active medium
Brewster angled windows
Radiofrequency pumping
Yield up to 20% higher than others classical CO2 laser
High-quality beam
4 High power CO2 Laser
Fast axial flow lasers
Increase gas flow
Heat exchanger
Convection
1 kW/m
4 High power CO2 Laser
Fast transverse flow lasers
Gas flow controlled by a turbine (100 Torr)
The laser beam crosses the cavity many times
10 kW/m
Poorer beam quality than axial flow lasers
4 High power CO2 Laser
TEA lasers
Transverse excited atmosphere lasers
Electric discharge : few tens of kV
10 atm : broadering effects
10 MW
Conclusion
Wide range of lasers design and outputs spectrum
Low power, High power
Pulsed or continuous mode
Many fields of application Dominate the cutting and welding business
Lower costs than YAG lasers
Infrared wavelength useful in surgery
Military range finding using LIDAR techniques
5
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