What is a fiber laser?

1.What is a fiber laser? 

Fiber laser is a kind of solid-state laser with rare-earth element-doped glass fiber as the gain medium, which has the features of high photoelectric conversion efficiency, simple structure and good beam quality. It has become the mainstream of laser technology development and industrial applications. Due to the small footprint of the fiber, the use of a wide range of occasions, in the field of manufacturing and processing of high usage. Fiber laser has strong processing adaptability and can be used in any occasion. In addition, its beam quality is better, which can minimize the cost and improve efficiency for manufacturing enterprises.

2. Characteristics of fiber laser

(1) The corresponding high-power, low-brightness LD light source in the absorption spectrum of rare earth elements can be pumped through the double-clad fiber structure to output a high-brightness single-mode laser.

(2) Compact and flexible design, high conversion efficiency, can work in harsh conditions, with good cooling system.

(3) Produces a good beam quality, high conversion efficiency, low threshold.

(4) The laser output in the 0.38-4um band can be realized by using different rare earth elements, and the wavelength can be easily selected and tuned, with a wide tuning range.

(5) High matching and good coupling with existing optical communication system.

(6) Low cost with fiber optic device and fiber optic, which can greatly reduce the structure cost.

3. Composition and principle

Like other types of lasers, fiber laser consists of three parts: gain medium, pump source and resonant cavity. It uses an active fiber with a core doped with rare earth elements as the gain medium. Semiconductor lasers are generally used as the pump source. The resonant cavity is generally composed of mirrors, fiber end faces, fiber ring mirrors or fiber gratings. The specific work process is as follows: in the working state, the active fiber (gain fiber) absorbs the energy provided by the pump source, which is amplified by the resonant cavity composed of the active fiber and fiber grating to amplify the output laser.

Seed source

Also known as the signal source, it is the object of radiation amplification in the laser amplification system. The laser providing the low power signal is used as the "seed" for the amplification system to amplify according to the state of the "seed".

Active Fiber

Active fiber as a gain medium, its role is to achieve the pump light to the signal light energy conversion, so as to achieve amplification.

Passive Optical Fiber

Passive fiber is mainly to achieve the function of light transmission, not involved in wavelength conversion. In the fiber laser system, there are mainly fiber gratings, passive matching fiber in the fiber isolator, passive multimode large-core diameter energy transmission fiber in the laser energy transmission components. At present, domestic suppliers of passive fiber products can basically meet the production needs, only a small number of passive fiber for ultra-high-power products still need to use imported fibers.