Study and design of cladding power stripper for high power fiber laser systems

Haixia An,Xiaogang Liu,Zhiyue Bi

doi:10.1017/hpl.2016.26

Abstract

Heat handling has been a significant problem of the high power fiber laser systems as the output power increases rapidly. Cladding power stripper (CPS) which is used to deal with the unwanted optical power and light is required for higher cooling ability. So the methods of stripping the unwanted light attracted much attention recently, and the thermal effect is given. However, few investigations focus on the dissipation of the heat converted from the unwanted light. In this paper, an approach of active cooling for CPS is demonstrated. This is achieved by using microchannel cooling technology in heat sinking in CPS to improve the efficiency of heat exchange. In order to explain the mechanism of CPS the function of it and consistence of categories of the unwanted light are detailed firstly. Then microchannel heat sinking is proposed and verified by the heat exchange theory. At last, the design of the CPS with microchannel heat sinking is shown and following experiment is conducted. The final temperature of the device with 1000 W cladding power was demonstrated at last to verify the ability of heat distribution of the CPS component. This suggests that these CPSs can be used to stripe a thousand of watts of light in high power double cladding fiber lasers.

Highlights

Fiber laser systems have many advantages over other laser systems, including high beam quality, high conversion efficiency, less-cost, light weight and small volume[1]
As the output power of double cladding fiber laser system (DCFLS) increases, the traditional cooling method could not suffer the strong heat, so we propose the microchannel heat sink of cladding power stripper (CPS)
The experiment of the CPS is conducted under the light propagate in fiber is 10 kW and the cladding power is 1000 W, which means that the unwanted light consists about 10% of the fiber laser power

Summary

Introduction

Fiber laser systems have many advantages over other laser systems, including high beam quality, high conversion efficiency, less-cost, light weight and small volume[1]. They have been widely applied in areas, such as optical sensing, advanced industrial processing, medical industries and military defense[2]. With the development of the double cladding fiber technology and laser diode pump technology, output power of the fiber laser systems has been increased rapidly. Thermal management has been a significant problem of the high power fiber laser systems as the output power increases rapidly. Methods of stripping the unwanted light in high power fiber laser attracted much attention recently and the thermal effect is given. A cooling method of using microchannel in cladding power stripper (CPS) was proposed and the final temperature of the CPS is given by a thermal camera

Function of cladding power stripper

Microchannel heat sink

Findings

Conclusion