Brillouin-gain spectra are measured for pure-silica core, GeO2-doped core, and P2O5-doped core single-mode fibers with different index profiles. A narrow-linewidth semiconductor laser operating at 828 nm is used as the pump light source. The spectral shape of the Brillouin gain is found to be strongly related to the refractive-index profiles. The Brillouin linewidths evaluated experimentally are 90 and 215 MHz for a step-index single-mode fiber and a graded-index single-mode fiber, respectively. The Brillouin Stokes shifts depend on the core/cladding dopant materials and their concentrations and range from 20 GHz for the P2O5-doped core fiber to 21.6 GHz for the pure-silica core fiber in the 0.8-μm-wavelength region.
© 1987 Optical Society of America
Original Manuscript: August 20, 1986
Manuscript Accepted: January 7, 1987
Published: April 1, 1987
Nori Shibata, Robert G. Waarts, and Ralf P. Braun, "Brillouin-gain spectra for single-mode fibers having pure-silica, GeO2-doped, and P2O5-doped cores," Opt. Lett. 12, 269-271 (1987)