Inscription of Bragg gratings in few-mode optical fibers

• 作 者: 郭鹏 饶云江 李登勇 龚元 Gangding Peng 吴宇 张伟利 吴慧娟
• 机 构: Key Lab of Optical Fiber Sensing and Communications (Education Ministry of China),University of Elec
• 出 处: Chinese Optics Letters
• 发表日期: 2013年02期
• 关键词: Bragg grating optic pitch graded quarter reflective realized length repetition

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 singlemode 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/με, 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 singlemode 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 / με, and 636.9 pm / m 1, respectively.