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