Carbon-dioxide laser construction and operation
- The active laser medium is a gas discharge cooled by air or water.
- The filling gas in the discharge tube consists of carbon dioxide, nitrogen, hydrogen, xenon, and helium.
- In flow-through lasers, carbon dioxide is continuously pumped through the discharge tube.
- Electron impact excites quantum vibrational modes of nitrogen, leading to population inversion.
- Carbon dioxide molecules emit radiation at 10.6μm or 9.6μm, maintaining population inversion.
- CO lasers require special materials for construction due to their infrared operation.
- Mirrors are typically silvered, while windows and lenses are made of germanium or zinc selenide.
- Gold mirrors and zinc selenide windows and lenses are preferred for high-power applications.
- Diamond windows and lenses are used in high-power applications and dirty environments.
- Historically, lenses and windows were made of salt, but they degraded with exposure to moisture.

Applications of Carbon-dioxide laser
- Industrial cutting and welding
- Medical surgeries and treatments
- Dermatology and skin resurfacing
- Dental procedures
- Microfluidic systems fabrication

Advantages of Carbon-dioxide laser
- High power output
- Efficient absorption by organic materials
- Precise and controlled ablation
- Minimal thermal damage to surrounding tissues
- Versatile wavelength range

Limitations of Carbon-dioxide laser
- Limited portability due to size and weight
- Higher cost compared to other laser types
- Safety concerns regarding eye protection
- Limited penetration depth in tissues
- Potential for scarring and pigmentation changes in skin resurfacing

CO2 Laser in scientific research and advancements
- Vibrational-rotational transitions of CO2 molecule
- Bidimensional codes recorded on glass surfaces
- Mechanisms of pulsed laser ablation of biological tissues
- Tissue effects of light from surgical lasers
- Mode-to-mode vibrational energy transfer in CO2 collisions
- Continuous-wave CO2 lasers
- High-power CO2-He lasers
- Tunable CO2 lasers
- Beam homogenizer and laser beam profiler
- Carbon-based curtain for stray laser light absorption

Carbon-dioxide laser (Wikipedia)

The carbon-dioxide laser (CO₂ laser) was one of the earliest gas lasers to be developed. It was invented by Kumar Patel of Bell Labs in 1964 and is still one of the most useful types of laser. Carbon-dioxide lasers are the highest-power continuous-wave lasers that are currently available. They are also quite efficient: the ratio of output power to pump power can be as large as 20%. The CO₂ laser produces a beam of infrared light with the principal wavelength bands centering on 9.6 and 10.6 micrometers (μm).