Comprehensive investigation of longitudinal spindle-shaped Yb-doped fibers for high-power laser applications

• DOI: 10.1364/oe.558282
• Publication Date: 2025-03-24T12:07:54Z
• Authors: Yun Ye; Zhiping Yan; Chunxiao Zhao; Xiaoyong Xu; Chen Shi; Xiaoming Xi; Hanwei Zhang; Xiaolin Wang; Zhiyong Pan; Zefeng Wang; Xiaojun Xu

We present a comprehensive investigation on the laser properties of longitudinal spindle-shaped Yb-doped fibers (SYDFs), focusing transverse mode instability (TMI) and stimulated Raman scattering (SRS), by conducting theoretical experimental comparisons with traditional uniform double-clad fibers. The underlying physical mechanisms for TMI SRS characteristics in SYDF amplifiers are revealed through detailed analysis. indicate that showcases slightly weaker threshold than fiber same core-to-cladding ratio, showing ∼4.6% ∼6.1% lower co-pump counter-pump schemes, respectively. But suppression ratio amplifier was ∼7.6 dB higher at power level 3.5 kW. When output these two scaled to 6 kW, still exhibited stronger performance as compared fiber. To best our knowledge, this is first comparison between SYDFs both regimes. This work provides significant reference design development what we believe be new silica-based alleviate high-power lasers.