Introduction
The fiber laser uses a fiber core doped with rare-earth ions as the gain medium, and the doped fiber is fixed on two mirrors to form a resonant cavity. When the pumped semiconductor laser passes through the fiber, the rare-earth ions in the fiber absorb the pump light, and the optical fiber absorbs its electrons. Once stimulated to a higher laser energy level, the particle inversion is realized, and the inverted particles are transferred from the high energy level to the ground state in the form of radiation, and the laser is output.
