Influence of Raman effect on the state of polarization evolution in a low-birefringence fiber

Abstract

In this paper, the linear polarization light satisfied nonlinear coupled differential equations containing the Raman effect are utilized in a low birefringence fiber. The coupling model equation satisfied by the Stokes parameters is derived by introducing the Stokes parameters. Poincaré sphere is used to analyze the influence of Raman scattering effect on the state of polarization evolution in the low-birefringence fiber. The results show that the state of polarization evolution can be changed and the polarization ellipticity can also be changed due to Raman scattering effect in the low birefringence fiber when between the input power and motion constants satisfy a certain relation.

High-power all-fiber linearly polarized Yb-doped chirped pulse amplifier based on active polarization control

“…With the enhancement of the pump power, the output power scaled linearly with a slope efficiency of 76.9%; whereas for the PER, it remained at around 12 dB when the output power was lower than 400 W. At the output power of 402.3 W, a PER of 11.4 dB was measured, corresponding to a highest horizontal linearly polarized light of 375 W, which shares 93.2% of the total output. Further increasing the operation power led to an apparent degrading of the PER to < 10 dB, mostly induced by the enhanced nonlinear effects, such as self-phase modulation and stimulated Raman scattering (SRS) [44,45] , as well as thermal effects under high-power operation. By employing a PC with a higher bandwidth and improving the control accuracy of the algorithm, it is expected to obtain a higher PER from the non-PM fiber amplifier.…”