A large core diameter rare earth doped optical fiber preform and its preparation method

Abstract

The invention discloses a large-core-diameter rare earth doped optical fiber preform and a preparation method thereof. The method comprises the steps that a first groove is burnt down in the first preset position of the tail end of a head pipe, a hole is formed behind the first groove, and a feeding pipe is connected with the formed hole; the head tube is weld-connected with the reaction tube, andthe welded reaction tube is connected with the tail tube; a loose layer is deposited on the inner surface of the reaction tube, and a second groove collapses at a second preset position at the tail end of the reaction tube; after the rare earth doping solution is injected from the feeding pipe, a feeding opening of the feeding pipe is sealed, and the reaction pipe is rotated to enable the rare earth doping solution to fully soak the loose layer; the reaction tube then is separated from the tail tube, the residual rare earth doping solution soaked in the loose layer is discharged, and the residual rare earth doping solution in the reaction tube is subjected to blow drying to finish doping; and the loose layer in the reaction tube doped with the rare earth solution is vitrified, and finallythe loose layer deposition and doping operations are repeated until the optical fiber preform meeting the requirement is prepared. The method is high in efficiency and simple to operate.

Description

technical field [0001] The invention belongs to the field of preparation of special optical fibers, and more specifically relates to a rare earth-doped optical fiber preform rod with large core diameter, high doping efficiency and high doping uniformity and a preparation method thereof. Background technique [0002] Fiber laser has the advantages of good heat dissipation, high efficiency, good beam quality, small size and light weight, etc. It shows extremely broad application prospects and great application value in the fields of material processing, intelligent manufacturing, medical treatment, and national defense. The core of various amplifiers or lasers is the gain medium rare earth doped fiber, so the high-efficiency fabrication of various rare earth doped fibers has become a key technology to promote the development of fiber lasers. [0003] The modified chemical vapor deposition method (Modified Chemical Vapor Deposition, MCVD) is currently widely used to prepare rar...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the above defects or improvement needs of the prior art, the present invention provides a large core-diameter rare-earth-doped optical fiber preform and its preparation method, thereby solving the existing problems in the preparation of active optical fiber preforms through the MCVD vapor deposition process. Technical problems that cannot effectively guarantee doping concentration, doping uniformity and background loss

Images