Jean Charles Jacques – Sébastien Bax – Nicolas Cortès

1. Jean Charles Jacques – Sébastien Bax – Nicolas Cortès CO2 Lasers Theory & Conception 07/01/2008

2. Contents Introduction 1 1 CO2 Lasers Theory 2 Low power CO2 lasers 3 High power CO2 lasers 4 5 Conclusion 5 1

3. Introduction 1 10.6 µm in the Infrared wavelengths Continuous power capability High efficiency Power from some tens of W to few tens of KW 2

4. CO2 Lasers Theory 2 • Vibration levels; Energy Storage Bending mode Symmetric Stretching mode Asymmetric Stretching mode Vibrational energy: Rotational energy: 3

5. CO2 Lasers Theory 2 • Transfer collision • E=2meV<25meV • Active medium composition • CO2: 10-20% • N2: 10-20% • He: 60-80% 4

6. Low power CO2 Laser 3 • Sealed CO2 Laser Regeneration of CO into CO2 Infrared specific optic Brewsterangledwindows DCDischarge Low power output Smallsizefora CO2 laser No heavy cost and maintenance 5

7. Low power CO2 Laser 3 • Waveguide CO2 Laser Very small BeO waveguide High pressure active medium Brewsterangledwindows Radiofrequency pumping Yield up to 20% higher than others classical CO2 laser High-quality beam 6

8. High power CO2 Laser 4 • Fast axial flow lasers Increase gas flow Heat exchanger Convection 1 kW/m

9. High power CO2 Laser 4 • 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

10. High power CO2 Laser 4 • TEA lasers Transverse excited atmosphere lasers Electric discharge : few tens of kV 10 atm : broadering effects 10 MW

11. Conclusion 5 • 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

12. Merci