Near-Field Lasing Dynamics of a Crystal-Glass Core鈥揝hell Hybrid Fiber

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• 作者：Chien-Chih Lai ; Chih-Peng Ke ; Cheng-Nan Tsai ; Chia-Yao Lo ; Ren-Chin Shr ; Mei-Hsin Chen
• 刊名：Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：August 29, 2013
• 年：2013
• 卷：117
• 期：34
• 页码：17725-17730
• 全文大小：485K
• 年卷期：v.117,no.34(August 29, 2013)
• ISSN：1932-7455

文摘

Nearly single-mode operation of a low-threshold continuous-wave crystal-glass core鈥搒hell hybrid fiber laser based on a multimode Cr⁴⁺:Y₃Al₅O₁₂ double-shell fiber is demonstrated. Nanoscale imaging of the optical intensity across the crystalline core allows for the direct assessment of the modal evolution, propagation modes, and near-field mode-field diameter at different working states. Below the lasing threshold of 60 mW, the near-field spatial modal distributions of the multitransverse modes are resolved and analyzed using a flattened Gaussian model. Above the threshold, nearly single-mode output with a beam quality factor of M² 1.1 is achieved by gain filtering, index guiding, and double-shell-based wave confinement, which are shown to agree well with the calculated light distribution.