CO2 Laser Machine – Cutting, Marking and Engraving Non-Metallic Materials
The CO2 laser is used to cut, mark and engrave non-metallic materials. Its focusing process creates extremely precise results that are difficult to achieve with a fiber laser.
The light from the laser tube is reflected up and down the length of the tube by mirrors that bookend it. The light builds in intensity until it is powerful enough to pass through a partially reflective mirror.
Light
CO2 lasers produce a beam of light with wavelengths in the infrared spectrum. Metals generally have poor absorption rates for energy radiations in this range and reflect the laser beams back toward the laser machine causing loss of energy. This makes laser engraving of metal difficult and expensive to accomplish.
To overcome this problem a CO2 laser can be fitted with a focusing lens. This focuses the energy radiation into a very small spot, allowing for better penetration into tissue. This is especially CO3 Laser Machine important in the case of papular pedunculated lesions such as skin tags.
Once the focused radiation enters the tissue it vaporizes some of the water in the tissue. This creates a chemical reaction that produces heat in the tissue and separates it from the surrounding tissues. This process is referred to as thermal separation.
The optimal parameters for a laser cut vary from material to material. This is why different laser cutters are used for various applications, ranging from industrial large-sized CO2 machines to a small home-based hobbyist laser cutter. These different CO2 laser cutters have varying capabilities which are determined by various factors such as their power, the type of gas that they use, and their beam diameter. Laser cutting is a very precise operation. Therefore, safety with lasers is paramount for the patient and all personnel in the treatment room. This includes protecting the eyes with goggles that include lateral shields. Also, damp drapes and cotton should be used to cover the patient, and these should remain moist throughout the procedure.
Mirrors
A carbon-dioxide laser produces a strong beam of infrared light. This is powerful enough to vaporise and cut through most materials. This power is concentrated into a small area by several mirrors and focusing lenses. It is this intense light that allows the laser to create sharp, precise cuts in non-metal workpieces.
During a CO2 laser operation, the light from the laser tube is reflected by mirrors inside the laser cavity. These mirrors redirect the beam vertically toward the focus lens. The focusing lens further concentrates the light into a focused beam of infrared light that can engrave or cut non-metal material.
The mirrors used in CO2 laser machines must have high reflectance and low absorption to minimize distortion of the laser beam. Mirrors typically consist of silvered glass or fused silica. Alternatively, NiCu gold plated copper mirrors are available and have shown to offer significant thermal and lifetime advantages over dielectric coated silica substrates. Windows for CO2 lasers are often made of either germanium or zinc selenide. They must have high transmittance and low absorption to prevent contamination of the laser beam.
Most CO2 lasers produce a beam with linear polarization. However, circular polarization is needed for some applications (such as cutting metal sheets). A mirror called a 90deg phase retarder can be used to convert a linearly polarized laser beam into a circular one.
Gas
Carbon Dioxide Laser Machine is a gas-discharge laser that emits light at a wavelength of 9,500 nm – 12,000 nm. It CO3 Laser Machine is able to cut and engrave materials such as wood, paper, plastics and metals. It is also used for dermalogical indications such as skin tag removal, seborrheic keratosis treatment and psoriasis removal. The CO2 Laser Machine has a very short pulse duration, which results in minimal tissue damage, and produces an average power of tens of watts to many kilowatts.
During an electric discharge, molecules of nitrogen and carbon dioxide in the active medium are pumped into excited electronic states. The nitrogen molecules then pump energy into carbon dioxide atoms, which cause the transition between vibrational and rotational levels to produce laser action. The laser energy is absorbed by the crystal and transferred into heat energy, which is then converted to light by an optical resonator.
The resulting laser beam can be mechanically or electronically gated or chopped to provide a series of square waveforms that induce different reactions. This allows the operator to select a mode that best suits the material being treated. For example, a higher peak power mode is suitable for cutting aluminium, whereas a lower power mode is better suited to laser engraving. The lens in the laser head can easily get contaminated with dust or dirt, so it must be carefully cleaned regularly to maintain optimal performance.
Power
The CO2 laser machine produces a beam of intense light that can be controlled to produce a variety of shapes and sizes. This allows it to cut through and engrave various non-metals and create a range of designs and patterns. Its non-contact process allows it to avoid damaging the workpiece, resulting in clean and precise results. The laser’s power can be varied depending on the material being worked with, so it is important to test and experiment with different settings before attempting to use the machine for a specific job.
CO2 laser machines are incredibly powerful. Even the smallest sealed CO2 laser looking much like a HeNe tube can produce many watts continuously, while industrial CO2 lasers may produce up to 10 kW for days at a time. They are also one of the few gas lasers capable of instant vaporization (& ablation) of tissue, giving them their reputation as ‘laser scalpels’.
Despite their huge output, CO2 lasers are relatively efficient. They have very high electron collision cross sections, so they rarely waste energy by ejecting N2 molecules into useless electronic states. They are also almost mono-isotopic – 99% 12C16O2 (13C, 17O, & 18O are very rare), which gives them an extra boost in efficiency. However, the power they deliver is so great that it can cause explosive reactions that release a jet of steam and particulate matter into the air; it is important to use a dedicated laser smoke evacuator for safety reasons.
