The CO2 laser, invented by c. Kumar n. patel at bell LABS in 1964, is an ancient technology in the rapidly changing photoelectric industry. Despite its long history, CO2 laser technology continues to thrive in the market thanks to its unique wavelength, power and spectral purity.
Because many natural materials and synthetic materials have a strong absorption peak of 9~12 microns, which happens to be the output wavelength of CO2 lasaerpointer band, which provides a lot of opportunities for CO2 laser in the field of material processing and spectral analysis. This band is also included in the atmospheric transmission window and is therefore ideal for many sensing and ranging applications (see figure 1).
A typical CO2 laser is formed by a gas discharge produced by a mixture of gases containing CO2 molecules. Because the vibrational and rotational energy levels of molecules are so close together, the photons produced by the transition of CO2 molecules between these levels are lower in energy and longer in wavelength than visible and near-infrared light.
CO2 lasers can provide power ranges from milliwatts to tens of thousands of watts, and can be used for instrumentation as well as for power cutting. Because of the high spectral purity of CO2 laser, the line width can be less than 1kHz without sacrificing power, and the conversion efficiency can be up to 10%. These characteristics make CO2 laser capable of new applications in the field of material processing, laser ranging and radar, thermal imaging visual AIDS and targeted medical applications.
Since its invention decades ago, countless CO2 lasers have been used in medical, manufacturing and scientific research fields, from the four-digit code printing on the production line of high-speed mineral water bottles in China to the welding of mercedes-benz car parts in Germany. Even as today’s fiber lasers are eroding the market for CO2 lasers, and quantum cascade lasers continue to create new fields, if CO2 lasers develop into dedicated fields, they will still win wide application in the market.
Despite these long-term advantages, CO2 lasers have been challenged in some ways. Fiber lasers and quantum cascade lasers have been extended to many applications previously dominated by CO2 lasers.
In industrial applications, high-power fiber lasers provide higher efficiency, better absorption of energy by metal materials, and more cost advantages. However, CO2 lasers are still the only way to process many non-metallic materials because they do not absorb the near-infrared wavelengths of fiber lasers.