CO2 lasers and fiber lasers, due to the different physical characteristics of lasers, have different processes for laser cutting machines using them. Of course, both have their own strengths and weaknesses, and each has its own advantages and disadvantages depending on the processing object.
A CO2 laser is a gas beam obtained by exciting carbon dioxide molecules, and its wavelength is 10.6 μm. A fiber laser is a crystal of a Yb (ytterbium) compound which is placed in a fiber as a medium, and this crystal is irradiated with a light beam to obtain a crystal beam. The solid laser has a wavelength of 1.08 μm. The physical characteristics of different wavelengths have a great influence on the processing characteristics of the two.
The concept of a fiber laser was originally recognized because it was a laser that could be transmitted through the fiber. The reason why it can propagate through an optical fiber is its wavelength, which is capable of propagating through an optical fiber because of its wavelength of 1.08 μm. The advantage of propagating with fiber is that its optical components have a long service life and high maintenance performance.
From the vibration oscillator to the processing point, the CO2 laser cutting machine transmits laser light by means of a mirror and generally propagates in an optical path isolated from the outside air. Although the light path is filled with air without ordinary dust or foreign matter, the surface of the mirror is attached to the dirt after being used for a long time and needs to be cleaned. In addition, the mirror itself is also lost due to the absorption of a small amount of laser energy and needs to be replaced. In addition, it is necessary to use multiple mirrors to adjust the reflection angle of the laser to propagate the laser from the oscillator to the processing point. Therefore, it requires a certain technical ability and management to maintain normal operation.
However, the fiber laser cutter travels from the oscillator to the processing point, and the laser propagates through one fiber. This fiber is generally called a light guiding fiber. Since the optical components such as the mirror are not required, and the laser light is propagated in the light guiding fiber isolated from the outside air, the laser is hardly lost, but strictly speaking, the laser repeatedly propagates around the periphery of the light guiding fiber. Therefore, the light guiding fiber itself will be somewhat depleted, but this life is several times longer than that of the mirror in the CO2 laser cutting machine. In addition, if the propagation path is above the minimum curvature of the light guiding fiber, the path can be freely determined, so adjustment and maintenance are also very convenient.
In the laser generation process (laser oscillator construction), the two are also different. The CO2 laser oscillator generates a laser by placing a gas mixed with CO2 in a discharge space. In order to ensure normal operation of the resonance length derived from the laser output power, optical components are disposed inside the vibrator, and the optical components inside the vibrator need to be periodically cleaned and replaced.
The fiber laser oscillator, as just mentioned, generates laser light inside the fiber and is isolated from the outside air. There are no optical parts, so there is almost no need for regular maintenance.
The maintenance cycle of the CO2 laser oscillator is set at approximately 4,000 hours, while the fiber laser oscillator is set at approximately 20,000 hours. As mentioned above, in terms of service life and maintenance performance, it can be said that there is a great advantage for the fiber laser processing machine.
In addition, we can also try to compare from the perspective of operating costs such as power consumption. The photoelectric conversion rate of the CO2 laser oscillator is said to be about 10 to 15%, while the fiber laser oscillator is about 35 to 40%. Since the photoelectric conversion rate is high, the amount of electric energy converted into heat dissipation is reduced, and the fiber laser processing machine can control the power consumed by the cooling device such as a cooler to be lower. In general, the vibration oscillator of the fiber laser processing machine has higher accuracy requirements for the cooling temperature management of the oscillator than the CO2 oscillator, but the vibration of the fiber laser processing machine is the same at the laser output power. The cooling capacity of 1/2 to 2/3 of the CO2 laser oscillator is sufficient. Therefore, considering the power consumption of all the devices of the laser processing machine, the fiber laser processing machine can operate under the power consumption of about 1/3 of the CO2 laser processing machine, which can be said to be a very energy-saving laser cutting machine.