Spectral control of optical gain in a rare earth-doped optical fiber using novel triple layered structures
- 作者：Kyungwhan Oh ; Seongwoo Yoo ; Uh-Chan Ryu ; Seungtaek Kim ; Un-Chul Paek ; Daniel B.S. Soh ; Jayanta K. Sahu and Johan Nilsson
- 关键词：Rare earth-doped fiber ; Optical waveguide design ; Evanescent wave ; Optical amplifier ; Fiber laser ; Er ; Sm ; Nd ; Tm ; C-band ; U-band ; W-type fiber
- 刊名：Optical Fiber Technology
- 出版年：2006
- 期刊代码：95_10685200
- 类别：ph
- 出版时间：October 2006
- 卷：12
- 期：4
- 页码：297-304
- 文件大小：405 K
摘要
Novel techniques to control the effective emission cross section of a rare earth-doped optical fiber with a functional cladding structure are reviewed for applications in active fiber devices. We discuss evanescent wave filtering (EWF) technique based on the overlap in the radiative transition cross sections between the emitting ion in the core and the absorbing ion in the inner cladding. Experimental applications of EWF concept are reviewed for a composite gain medium with the erbium ions in the core and samarium ions in the inner cladding for self-gain flattening in C-band. W-type three layered fiber structure is also analyzed in terms of modal guidance and location of the LP01 mode cut-off. Its application in neodymium and thulium-doped silica fiber laser is discussed to facilitate the radiative transition near 940 and 1600 nm region, respectively. The design concepts, fabrication process, and device performances are discussed for each application.