The CO2 laser is a gaseous laser with a wavelength of 10.6 μm that is fully absorbed through human biological tissue (all skin available). The sealed-off fractional CO₂ laser, whose output laser-light is delivered through an articulated arm, which has better direction and higher energy density.

The CO₂ laser operates in the invisible infrared waveband, and an aiming beam is required to see where the treatment beam will impact tissue more recently from a visible red diode laser. When the laser beam go through the focus lens, the produced heat will gasify the target tissue.

With fractional laser resurfacing the laser beam is broken up or fractionated into many small micro beams which are separated so that when they strike the skin surface small areas of the skin between the beams are not hit by the laser and left intact. These small areas of untreated skin promote a much more rapid recovery and healing with less risk of complications. The small areas treated by the fractional micro beams, called micro treatment zones, cause sufficient laser injury to promote new collagen production and resultant facial skin rejuvenation.