Experimental research of end-cap splicing technique for double-cladfibers based on CO2 laser

End-cap is effective for avoiding the fiber facet damage of pulsed double-clad fiber lasers under high peak power.In order to achieve end-cap assembling of large diameter double-clad fibers with low cost,a fiber end-cap splicing system based on a CO2 laser was designed and built.The method and process of fiber end-cap assembling was studied.The quality of the end-cap was evaluated by testing a high-peak-power pulsed fiber laser,which was assembled with end-caps using our method.The experimental results show that high-quality low-cost splicing of end-caps on double-clad fibers can be achieved by our splicing system.The end-cap spliced by our method can evidently increase the damage threshold of the fiber.Meanwhile,the influence of the end-cap on the efficiency and beam quality of the laser output is not obvious.