What is a carbon dioxide laser

During the critical period of transformation and upgrading in the manufacturing industry, Jiangpin Technology has chosen carbon dioxide lasers as its strategic development direction. This is not only due to its outstanding current market size and growth rate, but also because it aligns with the core trends of future manufacturing towards precision, flexibility and greenness. Especially in the process of China's transformation from a "manufacturing giant" to a "manufacturing power", the independent control of high-precision and advanced laser processing equipment has become a key link to ensure the security of the industrial chain. Now let's take a look at the carbon dioxide laser together:

Working principle：

Although carbon dioxide molecules can be directly excited to high energy levels, many studies have proved that the resonant energy transfer of nitrogen molecules is the most effective. Nitrogen molecules are excited by discharge to metastable vibrational energy levels and transfer the excited energy to carbon dioxide molecules when they collide with them. Subsequently, the excited carbon dioxide molecules mainly participate in laser transitions. Helium can reduce the number of low-energy particles in lasers and also carry away heat. Other components, such as hydrogen or water vapor, can help reoxidize carbon monoxide (CO, formed during discharge) to carbon dioxide.

CO2 lasers are typically capable of emitting wavelengths of 10.6 μ m, but there are dozens of other laser spectral lines in the 9-11 μ m region (especially 9.6 μ m). This is because the two different vibrational forces of carbon dioxide molecules can be used as low energy levels, and each vibrational force corresponds to a large number of rotational forces, thereby generating many sub-energy levels. Most commercially available CO2 lasers emit the standard wavelength of 10.6um, but there are also some devices that are specifically optimized for other wavelengths (such as 10.25um or 9.3um), and these devices are more suitable for certain applications such as laser material processing because they are more easily absorbed when irradiating certain materials (such as polymers). Special optical components may be required when manufacturing such lasers and using them for illumination, as standard transmissive 10.6um optical components may have overly strong reflections.

Output power and efficiency:

In most cases, the average output power ranges from tens of watts to several kilowatts. The power conversion efficiency is approximately 10%-20%, which is higher than that of most gas lasers and lamp-pumped solid-state lasers, but lower than that of many diode-pumped lasers. Due to its high output power and long emission wavelength, CO2 lasers require high-quality infrared optical components, which are usually made of materials such as zinc selenide (ZnSe) or zinc sulfide (ZnS). CO2 lasers have high power and high driving voltage, which poses serious laser safety issues. However, due to its long working wavelength, it is relatively safe for the human eye at low intensities.

CO2 laser types:

For laser power ranging from a few watts to several hundred watts, sealed tubes or flow-free lasers are typically used, where both the laser cavity and the gas supply are located within the sealed tube. Waste heat is transferred to the pipe wall through diffusion (mainly the effect of helium) or slow gas flow. This type of laser is compact in structure, sturdy and durable, and its working life can easily reach thousands of hours or even longer. At this point, the method of continuously regenerating gas needs to be adopted, especially by catalyzing the reoxidation of carbon monoxide to counteract the dissociation of carbon dioxide. The beam quality can be very high. High-power diffusion-cooled slab lasers place gas in the gap between a pair of planar water-cooled RF electrodes. If the electrode spacing is less than the electrode width, the excess heat will be effectively transferred to the electrodes through diffusion. To extract energy efficiently, a non-steady-state resonator is usually employed, and output coupling is carried out on the high-reflector side. Under reasonable beam quality, an output power of several kilowatts can be achieved. Fast axial flow lasers and fast cross-flow lasers are also suitable for continuous wave output power of several kilowatts and high beam quality. The excess heat is carried away by the rapidly flowing mixed gas, which is then reused for discharge after passing through an external cooler (heat exchanger). The mixed gas can be continuously regenerated and replaced occasionally. Cross-flow lasers can achieve the highest output power, but the beam quality is usually low.

The pressure of the laterally excited atmospheric laser is very high (approximately one atmosphere). Because the voltage required for longitudinal discharge is too high, a series of electrodes inside the tube need to be used for transverse excitation. This laser only operates in pulsed mode because gas discharge is unstable under high voltage. Their average output power is usually less than 100 watts, but they can also reach tens of kilowatts (combined with a high pulse repetition rate).
Solid-state lasers are lasers based on solid-state gain media (such as crystals or glasses doped with rare earth or transition metal ions), which can generate output power ranging from several milliwatts to several kilowatts. Many solid-state lasers use flash lamps or arc lamps for light pumping. These pumping sources are relatively inexpensive and can provide very high power, but their efficiency is rather low, their lifespan is average, and there are strong thermal effects in the gain medium, such as the thermal lensing effect. Laser diodes are most commonly used to pump solid-state lasers, and these laser-pumped solid-state lasers (DPSS lasers, also known as all-solid-state lasers) have many advantages, such as compact installation, long lifespan, and excellent beam quality. Its working mode can be continuous wave, that is, it can generate continuous laser output, or pulse type, that is, it can produce short-time high-power laser pulses.

Carbon dioxide lasers, with their unique wavelength advantages and wide material adaptability, have demonstrated irreplaceable strategic value in global industrial processing, medical aesthetics, and new energy fields. Despite the competitive pressure from fiber lasers in the field of metal processing, carbon dioxide laser technology still holds core competitive advantages and broad innovation space in specialized areas such as non-metallic processing, high-precision paint peeling, and deep skin treatment

For Jiangpin Technology, it should seize the historic opportunities presented by the upgrading of China's manufacturing industry and the global energy transition, and focus on three major directions: breakthroughs in high-power stability (such as addressing the "temperature quenching" effect), development of specialized scenarios (processing of new energy equipment), and customized solutions for small and medium-sized enterprises. By building a collaborative innovation system of "industry-university-research-application" and integrating into the regional industrial cluster ecosystem, Jiangpin Technology is expected to achieve a strategic transformation from a technology follower to an innovation leader during the critical period of technological revolution and market reconstruction of carbon dioxide lasers.