Germania-glass-core silica-glass-cladding single-mode fibers (Δ<i>n</i> as great as 0.143) with a minimum loss of 20 dB/km at 1.85 µm were fabricated by modified chemical-vapor deposition. The fibers exhibit strong photo-refractivity, with type IIa index modulation of 2×10<sup>-3</sup>. A Raman gain of 300 dB/(km W) was determined at 1.12 µm. Only 3 m of such fibers is sufficient for constructing the 10-W Raman laser at 1.12 µm with a 13-W pump at 1.07 µm.
© 2004 Optical Society of America
(060.2280) Fiber optics and optical communications : Fiber design and fabrication
(060.2290) Fiber optics and optical communications : Fiber materials
(060.2320) Fiber optics and optical communications : Fiber optics amplifiers and oscillators
(160.5320) Materials : Photorefractive materials
V. M. Mashinsky, V. B. Neustruev, V. V. Dvoyrin, S. A. Vasiliev, O. I. Medvedkov, I. A. Bufetov, A. V. Shubin, E. M. Dianov, A. N. Guryanov, V. F. Khopin, and M. Yu. Salgansky, "Germania-glass-core silica-glass-cladding modified chemical-vapor deposition optical fibers: optical losses, photorefractivity, and Raman amplification," Opt. Lett. 29, 2596-2598 (2004)