Detailed explanation of the principle and characteristics of fiber laser

Photocoupler

Introduction: Fiber lasers have many characteristics such as long life, small size, low price and flexible production. They are widely used in many fields such as laser fiber communication, medical equipment, automobile manufacturing, military defense and security. So the question is, what is the principle of fiber laser ? Please see below to break down ~~~

First, the principle of fiber laser - - Introduction

Fiber laser, the English name is Fiber Laser, is a device that uses a rare earth-doped glass fiber as a gain medium to generate laser output. The fiber laser can be developed on the basis of the fiber amplifier. Because the fiber core is very thin in the fiber laser, the internal power density of the fiber is high under the action of the pump light, which causes the "reverse number of particles" phenomenon in the laser energy level. On the basis of this, a resonant cavity is formed by a positive feedback loop, and a laser oscillation can be formed at the output.

Second, the principle of fiber laser - - structure

The structure of a fiber laser is similar to that of a conventional solid-state laser or gas laser. It consists mainly of a pump source, a gain medium, and a resonant cavity, as shown in the following figure. The pump source is generally a high-power semiconductor laser, the gain medium is a rare earth-doped glass fiber, and the resonant cavity is composed of a coupler or a fiber grating.

Third, the principle of fiber laser

In the above figure, the pump light emitted by the pump source is coupled into the gain medium through a mirror. Since the gain medium is a rare earth doped fiber, the pump light is absorbed, and the rare earth ion generating level of the photon energy is absorbed. The transition and the realization of the population inversion, the inverted particles pass through the resonant cavity, transition from the excited state back to the ground state, release energy, and form a stable laser output.

Fourth, the principle of fiber laser - - Features

Feature 1: Due to the small diameter of the fiber core, high power density is easily formed in the core. Therefore, the fiber laser has high conversion efficiency, low enthalpy, high gain, narrow line width, and is convenient. Efficient implementation of connectivity to current fiber optic communication systems.

Feature 2: Because the fiber has good flexibility, the fiber laser has the characteristics of small size, flexibility, compact structure, high cost performance, and easier system integration.

Feature 3: Compared with traditional solid-state lasers and gas lasers, fiber lasers have higher energy conversion efficiency, compact structure, high reliability, and are suitable for mass production.

Feature 4: Compared with semiconductor lasers, fiber lasers have better monochromaticity, smaller chirps and distortions during modulation, and less coupling loss with optical fibers.

Principle of fiber laser