The CO2 laser beam is created by harnessing the reaction of a mixture of gases within a sealed tube. These gasses are known collectively as the laser medium.
The tube, or cartridge as it is otherwise known, can be made of glass or metal. Metal tubes offer greater efficiency and stability with a significantly longer lifetime. Glass tubes offer little in the way of any performance benefit as they are unreliable and unstable but they are very low cost.
The entire range of CO2 laser systems supplied by Laserite use all-metal tube technology manufactured by Synrad; the World's largest manufacturer of sealed metal laser tube technology. Synrad manufactures thousands of lasers every year and has a reputation for supplying high quality lasers with long working lifetimes.
Radio Frequency (RF) is used to 'excite' the molecules of the gases (the laser medium) and so create the laser beam.
The main reactional gas within the tube is CO2 hence the title; CO2 laser. The wavelength of this type of laser is 10.6µm, which reacts with materials such as wood, paper, card, some plastics, textiles, ceramics, stone, etc.
At low power (<250w) there is not enough laser energy to cut metals. When cutting metals with a C02 laser, generally power levels in excess of 1kw are used in combination with an active gas assist.
Heat is generated as a by-product of the process of creating the beam and this must be controlled in an efficient way to prevent the tube from over-heating. This can be via a recirculating water chiller or by air-cooling with fans.
Water-cooling the laser offers the best form of heat removal from the tube, however, water-cooling adds significantly to the price, overall footprint and running costs of the system.
Water-cooling is best suited to:
Air-cooling is well suited to:
For most installations air-cooling the laser is adequately efficient and offers significant savings in terms of system cost and footprint.
Laser power is controlled via the software as a percentage of maximum potential output (0-100%). To increase effective power the laser is pulsed. Pulsing is controlled by frequency in kHz (how many pulses are fired per second). For most common applications this is typically between 500Hz and 10kHz.
Laser power and frequency as well as motion control settings can be varied to provide for a wide variety of cutting and marking applications.
The beam exits the laser tube with a diameter of approximately 3.5mm (depending on model) where optical components deliver and further enhance its effective energy at the workpiece.