Amplification in Extended Transmission Bands Using Bismuth-Doped Optical Fibers

Bismuth-doped optical glasses emit NIR luminescence in an ultrabroad spectral region of 1000-2000 nm. It makes Bi-doped glasses and glass optical fibers a promising active medium for the creation of Bi-doped fiber lasers and broadband optical amplifiers for this spectral region. Since the first fabrication of Bi-doped fibers in 2005 a large number of papers devoted to the development of Bi-doped fiber lasers and optical amplifiers have been published. It has been shown that Bi-doped fibers are a new breakthrough in active laser materials. But there still remains one important problem-up to now the nature of the Bi-related NIR emitting centers is not clear. This prevents one to optimize the technology and compositions of Bi-doped fibers to improve the parameters of Bi-doped fiber devices. This paper reviews the recent results on the luminescence properties of various Bi-doped optical fibers and the development of Bi-doped fiber lasers and optical amplifiers for the 1150-1550 nm spectral region.