Temperature characteristic of a gain fiber core in distributed side-coupled cladding-pumped fiber amplifiers with different pump schemes

Abstract

In this paper, we study the temperature characteristic of a gain fiber core in distributed side-coupled cladding-pumped (DSCCP) fiber amplifiers by optical frequency domain reflectometry (OFDR). To the best of our knowledge, this is the first temperature distribution measurement of a fiber core in DSCCP fiber lasers. The temperature distributions are also firstly measured among forward, backward, and bidirectional pump schemes. In addition, the bidirectional pump scheme has lower temperature distribution than unidirectional pump schemes. The experimental fiber core temperature is in according with the numerical simulation, which was once introduced for the temperature study of DSCCP fiber amplifiers. By experimental measurement and theoretical modeling, it is found that the maximum core temperature is several tens of centimeters away from the injected end of the DSCCP fiber, such that it will distribute the heat load along the longitudinal direction and reduce the maximum thermal load with better thermal management advantages than ordinary double cladding fiber (DCF).