CO₂ laser excitation process

CO₂ laser, the main substance of the work by the CO₂, nitrogen, helium three gases composition. Wherein CO₂ laser radiation is generated gas, nitrogen gas and helium as the secondary gas. Added helium, can accelerate the pre-010 level thermal relaxation process, thus facilitating laser level 100 and 020 evacuated. Mainly from the nitrogen added in CO₂ laser energy transfer role for CO₂ laser tube output level and the number of particles accumulate high-power high efficiency play a strong role on the laser. CO₂ laser transition of molecular energy level diagram of CO₂ laser excitation conditions: discharge usually enter tens or hundreds mA mA DC current. Discharge nitrogen molecules in the discharge vessel within the gas mixture due to the collision of electrons which are aroused. Then they are excited nitrogen molecules and CO₂ molecules collide, N2 molecules transfer their energy to the CO₂molecule, CO₂ molecules from the low energy level transition to the formation of the number of particles emitted laser energy level inversion.

CO₂ laser resonator cavity common concave mirror with K8 optical glass or optical quartz, processed by the National Cheng Kung University radius of curvature of the concave mirror coated with a metal film with a high reflectance - gold-plated film at a wavelength 10.6μm the reflection rate of 98.8%, and chemically stable. Light infrared light emitted carbon dioxide. Therefore, the mirror needs to be applied infrared light through the material, because ordinary optical glass impervious to infrared light. It requires the total reflection mirror in the center of a small hole open. Resealing on a permeable material 10.6μm infrared laser, to seal gas. This makes the laser resonator from the outer part of the cavity output orifice to form a laser beam.
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