摘要
Few-mode fiber Bragg grating （FM-FBG） has wide applications in the field of multi-wavelength fiber lasers and fiber-optic sensing. In this letter, FBG is successfully written in a novel type of FM fiber （FMF） based on 248-nm excimer laser and a uniform phase mask. A low-loss coupling between the FMF to a single- mode fiber is realized by a graded-index multi-mode fiber with a length of about a quarter pitch. The sensing properties of the FMF grating are further investigated. The experimental results indicate that the novel FM-FBG has sensitivities of temperature, strain, and bending of 11.2 pm/~C, 1.3 pm/pg, and 636.9 pm/m-1, respectively.
Few-mode fiber Bragg grating （FM-FBG） has wide applications in the field of multi-wavelength fiber lasers and fiber-optic sensing. In this letter, FBG is successfully written in a novel type of FM fiber （FMF） based on 248-nm excimer laser and a uniform phase mask. A low-loss coupling between the FMF to a single- mode fiber is realized by a graded-index multi-mode fiber with a length of about a quarter pitch. The sensing properties of the FMF grating are further investigated. The experimental results indicate that the novel FM-FBG has sensitivities of temperature, strain, and bending of 11.2 pm/~C, 1.3 pm/pg, and 636.9 pm/m-1, respectively.
基金
supported by the National Natural Science Foundation of China(Nos.61107073,61107072,and61106045)
the Fundamental Research Funds for the Central Universities of China(No.ZYGX2011J002)
the Research Fund for the Doctoral Program of Higher Education of China(No.20110185120020)
the Open Research Fund of State Key Laboratory of Transient Optics and Photonics,Chinese Academy of Sciences(No.SKLST201005)
