RARE-EARTH-DOPED, LARGE MODE AREA, MULTIMODE, HYBRID OPTICAL FIVER AND DEVICE USING THE SAME

文件类型：PDF文档
文件大小：109K
PROBLEM TO BE SOLVED : To provide a method for improving an optical coupling efficiency of a large mode area and rare earth doped fiber (LMA and REDF). SOLUTION : This large mode area and rare earth doped fiber is constituted so as to cope with a multiple transverse mode of signal radiation in a core region. The fiber is designed to include at least two-axis portions having different properties. In a first axis portion, a transverse refractive index profile is not uniform in the radial direction and is characterized by the radial depression in the radial direction of a refractive index. The first portion corresponds to two or more transverse modes. In a second axis portion, the transverse refractive index profile is more uniform than the profile of the first portion. The two portions are coupled so as to be thermally insulated from each other. In detail, the second portion is a termination portion of the fiber which makes the coupling to other components easy. In one embodiment, the first portion satisfies M12>1.0 and the second portion satisfies M22≪M12. In a preferable embodiment, it is M12≫1.0 and M22≈1.0. COPYRIGHT : (C)2007, JPO&INPIT