High-power Raman optical fiber amplifier based on cladding pumping

Abstract

The invention belongs to the technical field of fiber lasers, and provides a high-power Raman optical fiber amplifier based on cladding pumping. The amplifier comprises a seed source (1), a high-powerfiber laser pumping source array (2), a pumping signal combiner (3), a Raman optical fiber (4) and an end cap (5). The seed source (1) is a laser source with signal light wavelength and connected with the central signal arm of the pumping signal combiner (3). The output arms of the high-power fiber laser pumping source array (3) are connected with the pumping input arms of the pumping signal combiner (3) respectively. The output end of the pumping signal combiner (3) is connected with the Raman optical fiber (4), and the other end of the Raman optical fiber (4) is connected with the end cap (5). Raman laser is output through the end cap (5). The Raman optical fiber (4) is a double-clad passive optical fiber. The output optical fiber of the pumping signal combiner (3) and the tail fiber ofthe end cap (5) are double-clad passive optical fibers which are the same as the Raman optical fiber (4).

Description

Technical field [0001] The invention generally belongs to the technical field of fiber lasers, and specifically relates to a high-power Raman fiber amplifier based on cladding pumping. Background technique [0002] Most laser applications not only have strict requirements on laser power and wavelength, but also on brightness. Brightness is defined as the laser power emitted per unit area and unit solid angle, which represents the ability of the beam to be focused. Generally speaking, for lasers with the same power, the higher the brightness, the better the beam quality and the better the effect. Commonly used M 2 The factor evaluates the quality of the laser beam, and its ideal value is 1, which corresponds to the fundamental mode in the fiber; the larger the value, the worse the beam quality. [0003] The beam purification in the cladding-pumped Raman fiber laser refers to the laser gain generated by stimulated Raman scattering in the passive fiber of the double-cladding structu...

AI Technical Summary

Problems solved by technology

However, fiber optic oscillators require special custom-made fiber gratings based on double-clad fibers, which are expensive, and the beam purification at high power is affected by temperature, and there are great difficulties in further brightness improvement.

On the other hand, the Raman fiber amplifier without fiber grating has the potential of power amplification. However, the injection of its seed and pump is based on the power beam combiner, which lacks the consideration of maintaining the brightness of the seed laser. After passing through the power beam combiner The brightness of the seed has dropped seriously, resulting in a lower brightness of the laser beam after amplification, and the beam purification effect is not obvious

Images