CO2 Experimental Laser

The CO2 Laser, is undoubtedly considered to be the most important technical development since the discovery of the laser in 1961. Many types of laser were discovered and developed in the 60‘s. But no one had the idea until 1964, when C. Patel reported about a CO2 Laser, of less than a milliwatt output power, having at its disposal tremendous technical potential. Today, after more than 33 years of stormy laser development, the CO2 Laser forms an indispensable tool of industrial production. When compared with other lasers, the CO2 Laser is distinguished firstly by its much higher efficiency and extreme high power output and secondly by the sole dependence of the power limit only on the limits of destructibility of the optical resonator‘s components. The present technology enables the Laser to achieve output powers of up to 20 kW. With 10 kW power, one can cut through a centimetre thick steel sheet. CO2 Lasers of under 100 Watt power output have however, achieved the most frequent application usage. The CO2 lasers emission wavelength is 10.6 µm and falls in the range of infrared radiation, which is also referred to as thermal radiation.
The interaction of this radiation with matter is thus thermal. The coherence of the laser beam permits it to be focused on a diameter of 10 µm. Consequently, the CO2 Laser makes it possible to concentrate extremely high heat radiation onto exact points of particular components. Depending on the laser power, different effects are achieved e.g. simple heating for soldering purposes or thermal colouring for inscriptions on plastics. At higher power levels, the material locally melts and with the help of a gas beam (e.g. oxygen) blown coaxial to the laser beam the steel is cut or bored. A further application area is laser hardening. Also in the medicine there are various applications e.g. operation of high blood organs, such as the liver, due to high cost of blood stemming which involves high risk. On the contrary, the CO2 Laser beam burns the operational area, coagulates the cut and blocks the blood vessels at the same time.

The Laser Design

The laser head is designed as an open frame resonator where all components can be seen through a translucent cover. The laser mirror of the optical resonator can be aligned by means of fine pitch screws for best performance.

The walls of the laser workstation are made out of a translucent material which absorbs the generated laser radiation. therefore, the material processing can be observed without danger to the human eye or skin. The laser can only be activated when a variety of safety interlocks are closed. Opening the door of the workstation shuts down the operation immediately, so that the entire laser system is classified as Class 1 Laser.

The electronics cabinet contains the high voltage supply for the CO2 Laser and a closed loop water cooling system. A vacuum pump is used to control the proper pressure and gas flow inside the discharge tube and a suction pump removes residue of the material processing.