求把这段话翻译成英语

Optical fiber laser is to use mixed ree glass fiber as the laser gain medium, fiber lasers in fiber amplifier developed on the base of pump: in under the effect of fiber in high power density, easily formation cause of the laser energy laser working substance "particle count in reverse", when properly join is a feedback loop (constitute a resonant cavity) can be formed laser oscillation output. This paper introduces the optical fiber laser composition, principle and development, expounds its in industrial, commercial and communication system, the military, medicine, etc, and its development trend were discussed.

Fiber laser is the rare-earth element-doped glass fiber used as the gain medium of the laser, fiber laser fiber amplifier can be developed based on: the role of the pump under the formation of optical fiber with extremely high power density, resulting in the laser material laser work level "population inversion", when adding the appropriate positive