Two-Step Tapering-Collapse Method Enables Element-Interdiffused Cladding for Enhanced Laser Amplification in Yb:YAG Single Crystal Fibers
Abstract
The development of high-power single crystal fiber (SCF) lasers is critically hindered by the lack of a reliable cladding scheme to confine the optical mode and ensure beam quality. Here, we propose and demonstrate a two-step tapering-collapse method for the first time to fabricate a high-quality cladding on Yb:YAG SCFs based on elemental interdiffusion. This in-situ formed crystalline transition layer with a graded refractive index effectively suppresses lattice mismatch and abruptly mitigates core-cladding interfacial stress. Consequently, the numerical aperture of the SCF is significantly reduced from 0.280 to 0.199. In a master oscillator power amplifier configuration, the clad SCF delivers a remarkable 46.7% enhancement in slope efficiency compared to its bare counterpart, accompanied by a substantially improved near-field beam profile. This work establishes a facile and effective route to high-performance clad SCFs, unlocking their full potential for next-generation extreme-condition lasers.
Cite
@article{arxiv.2603.17700,
title = {Two-Step Tapering-Collapse Method Enables Element-Interdiffused Cladding for Enhanced Laser Amplification in Yb:YAG Single Crystal Fibers},
author = {Xiangfei Zhu and Xiaofei Ma and Chenxin Gao and Tao Wang and Zhen Huang and Jiajia Zeng and Dongran Shi and Xuanfeng Zhou and Baolai Yang and Zilun Chen and Hu Xiao and Feng Xiong and Pengfei Ma and Jian Zhang and Zhitai Jia and Zefeng Wang and Xutang Tao},
journal= {arXiv preprint arXiv:2603.17700},
year = {2026}
}