Fused cone type long-period fiber bragg grating, preparation device, preparation method and laser system

Abstract

The invention provides a fused cone type long-period fiber bragg grating, a preparation device, a preparation method and a laser system. The fused cone type long-period fiber bragg grating comprises an optical fiber, the optical fiber is provided with more than one taper area, the distance between every two taper areas is equal, the distance equals the period of the fused taper type long-period fiber bragg grating, and the taper areas are formed through fused biconical taper. According to the invention, the long-period fiber bragg grating is prepared by using a periodic fused biconical taper method, limitation of the diameter of the optical fiber can be broken through, preparation of the long-period fiber bragg grating can be realized on the optical fiber with any size, the insertion lossis small, period setting is flexible and controllable, and the bandwidth is larger. The fused cone type long-period fiber bragg grating is arranged in the fiber laser system, stimulated Raman scattering in the fiber laser can be greatly improved, and the long-period fiber bragg grating can be widely applied to the fiber laser.

Description

technical field [0001] The invention relates to the technical field of writing and application of optical fiber gratings, in particular to a fusion-tapered long-period optical fiber grating, a preparation device, a preparation method and a laser system. Background technique [0002] The long-period fiber grating can realize the coupling between the core mode and the co-propagating core mode and the cladding mode, and belongs to a transmission-type band-stop filter with excellent performance. Because of its small size, small insertion loss, no retroreflection, low manufacturing cost, corrosion resistance, and the ability to embed materials, this device has important value and wide application in the fields of optical fiber communication, sensing, etc. prospect. In recent years, long-period fiber gratings have been proven to play an important role as filters in fiber lasers. [0003] A very important limiting factor in fiber lasers is stimulated Raman scattering. Since the e...

AI Technical Summary

Problems solved by technology

However, for high-power fiber lasers, the commonly used fibers are large in size, such as 20 / 400, 30 / 600 double-clad fibers, etc., and common preparation methods such as carbon dioxide laser point-by-point writing and UV amplitude template exposure are difficult. Fabrication of long period fiber gratings directly on fibers of this diameter

The femtosecond laser can directly act on the fiber core to form ablation, but the long-period fiber grating prepared by this method has a high temperature rise coefficient in the fiber laser, and the bandwidth is small, and the filtering of Raman scattered light is relatively poor. thorough

Images