[OPTICAL REVIEW Vol. 7, No. 4 (2000) 297-302]

Output Characteristics of High-Power Continuous Wave Raman Fiber Laser at 1239 nm Using Phosphosilicate Fiber

Mahendra PRABHU1, Nam Seong KIM1,2 and Ken-ichi UEDA1

1Institute for Laser Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585 Japan, 2Information and Telecommunication Technology Center, The University of Kansas, 2291 Irving Hill Road, Lawrence, Kansas, 66045 U.S.A

(Received December 7, 1999; Accepted March 16, 2000)

A high-power singlemode Raman fiber laser (RFL) with maximum output power of 4.11 W and maximum power conversion efficiency of 47.40% at 1239 nm is realized using continuous wave 8.4 W Yb-doped double-clad fiber laser as a pump, 700 m phosphosilicate fiber, and a Raman cavity formed by a pair of fiber Bragg grating mirrors at 1239 nm. The output characteristics of the RFL at 1239 nm for different fiber lengths and output mirror reflectance are reported. Theoretical simulation is done to numerically optimize for fiber length and output coupler reflectivity to obtain maximum first Stokes power.

Key words : Raman fiber laser, phosphosilicate fiber, double-clad fiber laser, optical fiber, stimulated Raman scattering, fiber Bragg grating