Power-dependent effective reflection of fiber Bragg grating as output coupler of Ytterbium-doped fiber laser

In this paper, we discuss the effective reflection of a fiber Bragg grating and its dependence on laser power when it is used as an output coupler of an ytterbium-doped fiber laser (here the effective reflection is considered to be a part of intracavity laser power reflected by the grating back to the laser cavity). We propose and discuss an experimental technique based on spectral and power analysis and derive simple formulae that permits one to obtain the intra-cavity power and the grating effective reflection. We show that, due to spectral broadening, the effective reflection dramatically decreases with increasing laser power, the effect precisely fitted using the derived formulae describing this quantity. The experimental part of the present study is based on an analysis of the operational regime of a long-wavelength ytterbium-doped fiber laser.

Automated summary

This paper discusses the effective reflection of a fiber Bragg grating and its dependency on laser power when used as an output coupler in a ytterbium-doped fiber laser. The authors propose an experimental technique based on spectral and power analysis and derive simple formulas to obtain intra-cavity power and grating effective reflection. The study shows a significant decrease in effective reflection with increasing laser power due to spectral broadening.