Liangjin Huang

Nonlinear effects hinder the ultimate performance of high-power laser delivery in solid-core optical fibers. Mitigating nonlinear effects through suppressing the unexpected gain is a promising strategy. In this work, we present a high-fidelity and Raman-free laser delivery employing the over 20-meter-length all-solid photonic bandgap fiber (AS-PBGF), which is designed for spectral filtering at the stimulated Raman band.

Dynamic transverse mode instability (TMI) has become one of the primary limitations for power scaling of high-power fiber lasers. Experimental evidence has shown that static mode degradation can suppress the dynamic TMI effect. This study reveals the physical mechanisms behind the mitigation of dynamic TMI in two-mode fiber lasers through static mode degradation.

The separate diagnosis of mode degradation in few-mode fiber components (FMFCs) is a challenging task due to the reciprocal mode cross talk. In this work, we propose the group delay stretching, combined with the extended spatially and spectrally (S2) resolved imaging technique, to decouple and analyze the mode coupling within the body of the FMFC with short-length pigtails.