In the fiber core doped with rare earth ions, pump light through the fiber, rare earth ions in the core to absorb the pump light, jump to the laser on the energy level, resulting in particle number inversion. After the reversal of the particles in the spontaneous radiation photons or special injection of photons induced by excited radiation jump to the laser energy level, while emitting the same photons with the induced photons, such a process of avalanche, and then emit a laser. This is the basic principle of a fiber laser.
The basic structure of the fiber laser consists of gain medium, resonant cavity and pump source. Gain medium doped with rare earth ions for the fiber core, doped fiber placed in the two reflectivity after the selection of the cavity between the mirror, pump light from the fiber laser cutter laser coupled into the fiber on the left side of the cavity mirror, through the collimated optical system and filter to get the output laser.
Theoretically, only the pump source and gain fiber is a necessary component of the fiber laser, while the resonant cavity is not an indispensable component. Resonant cavity mode selection and increase the length of the gain medium in the fiber laser can not be used, because the long fiber itself can be very long, thus obtaining a very high one-way gain, and the waveguide effect of the fiber can play a role in mode selection. However, in practice, people generally want to use a shorter fiber, so most cases use a resonant cavity to introduce feedback.
Fiber laser cutting machine because it can be transmitted through the fiber, the degree of flexibility increased, fewer failure points, easy maintenance, speed odd, so in the cutting of thin plates within 4mm fiber cutting machine has a great advantage, but by the solid-state laser wavelength it is in the cutting of thicker plates when the quality is poor.
Fiber laser laser cutting machine wavelength of 1.06um, not easy to be absorbed by non-metallic, so can not cut non-metallic materials. Fiber laser photoelectric conversion rate of up to 25% or more, in terms of electricity consumption, supporting cooling system, etc. The advantages of fiber laser are quite obvious. According to safety standards, the laser hazard level is divided into 4 levels, fiber laser due to the short wavelength of the human body due to eye damage, belongs to the hazardous first level, for safety reasons, fiber laser processing needs to be fully closed environment. Fiber laser cutting machine as an emerging laser technology, popularity is far less than CO2 laser cutting machine.