Exploring 3 Types of Lasers: The Heart of Laser Equipment

The widespread use of laser technology in industries has become prevalent.

Lasers are utilized in a variety of fields including automobile manufacturing, power batteries, mobile phone production, aerospace, medical equipment, defense, and military.

Laser technology has become an indispensable support technology for many industries. One of the cores of intelligent manufacturing is photoelectric technology, and laser is at the core of photoelectric technology. The significance of laser, as the core of many laser equipment, is evident.

For example, in a laser cutting machine, the laser is focused into a high-power density laser beam through the optical path system. The beam then melts or boils the surface of the workpiece and a high-pressure gas blows away the molten or vaporized metal. As the relative position of the beam and workpiece moves, the material forms a slit, resulting in a cut.

The choice of laser is crucial in determining the processing object and conditions. Currently, the three industrial lasers with high market share are Solid-state lasers, CO2 lasers, and Fiber lasers, classified by their gain medium.

Solid-state Lasers

The solid-state laser employs a solid-state laser material as its active medium. This substance is energized through various means such as lamps, semiconductor laser arrays, and other laser pumping sources. The most widely utilized solid-state laser is the YAG solid-state laser.

From processing perspective:

YAG solid-state lasers can cut a variety of high-reflection materials, such as aluminum and copper, which cannot be cut with CO2 or fiber lasers.

However, they have low power and can only be used on thin plates that are less than 8mm thick.

While the cutting efficiency is lower and slower than fiber laser cutting, YAG solid-state lasers occupy less space and provide cost savings in terms of space utilization.

From maintenance cost perspective:

The YAG solid-state laser, which has been developed over many years, is relatively inexpensive. However, its photoelectric conversion efficiency is only 3%.

CO₂ Lasers

A gas laser using CO2 gas as the active medium operates at a wavelength of approximately 10.6 μm in the infrared spectrum, making it a significant industrial laser.

From processing perspective:

The CO2 laser cutting machine boasts a broad cutting capacity and can handle thicker metal plates with ease. It’s not limited to metal materials either, as it can also cut non-metallic materials like acrylic, PVC, and wood.

The cutting result is characterized by its high quality and smooth finish, however, the cutting speed is reduced when working with thicker plates.

From maintenance cost perspective:

The CO2 laser cutting machine has high costs for both processing and maintenance. The front and tail mirrors are costly, and the lifespan of the turbine bearings is limited to just 8000 hours, resulting in a replacement cost of 80,000 yuan per pair. Additionally, the machine’s photoelectric conversion efficiency is only around 10%.

The laser structure of the CO2 laser cutting machine is complex, making maintenance difficult and requiring high levels of operation.

Fiber Laser

The term “fiber laser” refers to a laser that utilizes a rare-earth-doped glass fiber as its gain medium. Optical fibers are made from SiO₂ as the matrix material and they work by using total internal reflection to guide light.

The applications of fiber lasers are numerous and diverse, ranging from fiber optic communication and remote sensing in space, to industrial uses in shipbuilding and automobile manufacturing, as well as laser engraving, marking, cutting, and printing. They are also used in military defense, medical equipment, and large infrastructure projects, and serve as pump sources for other types of lasers.

From processing perspective:

The fiber laser cutting machine has the ability to cut all types of metal plates with great speed, making it 2 to 3 times faster than a CO₂ laser cutting machine when cutting thin plates. The cross-section quality is smooth and with the increase in power, it can cut thicker plates.

The beam quality is exceptional, with a small focal spot diameter, allowing for precise processing and making it suitable for flexible processing. In terms of maintenance cost, the fiber laser cutting machine is cost-effective, with a photoelectric conversion efficiency of up to 30%. It also offers maintenance-free and adjustment-free benefits, making it highly stable and able to be used in harsh working environments.

With the rapid development of fiber lasers, the market share of CO₂ lasers is continuously decreasing, especially in the field of metal processing. In just a few years, CO2 lasers have lost their dominant position.

It is undeniable that there are still many applications for which other types of lasers are not suitable and only CO₂ lasers can be used. The CO₂ laser’s unique wavelength makes it ideal for processing certain non-metallic materials, such as coding the production date on beverage bottles.

Furthermore, CO₂ lasers still have advantages in the field of cutting thick plates. The integration and automation of laser processing, through the use of industrial robots, continues to improve, leading to multi-dimensional processing capabilities, including three-dimensional welding, marking, and cutting.

The use and scope of laser technology are constantly expanding.