Large mode field active optical fiber and manufacture method thereof

Abstract

A large mode field active optical fiber and manufacture method thereof is provided. The large mode field active optical fiber is formed by drawing a fiber core (), a quartz glass internal cladding (), a quartz glass outer cladding (), and a coating (). The quartz glass internal cladding (), the quartz glass outer cladding (), and the coating () are sequentially coated on the outer surface of the fiber core (). The fiber core () is formed by depositing, melting, and shrinking the tetrachlorosilane doped with rare earth ions in a quartz glass tube. The refractive index of the fiber core () is a graded refractive index, and the section parameter a thereof is 1≦α≦3. The appearance of the quartz glass inner cladding () is regular multi-prism shaped. The large mode field active optical fiber provides an approximate single mode output, increases the capacity of bearing the laser power for the active optical fiber, increases the quality of the light beam of the output laser, avoids the problem that there is a hollow ring in the output laser, increases the reliability of the high power fiber laser, increases the utilization efficiency of the raw materials, and reduces the manufacture cost.