We experimentally demonstrate efficient optical carrier reduction of microwave signals with a single-mode 1.5-μm wavelength Brillouin all-fiber ring laser. Because of the tunable optical coupling, the lasing threshold of the short-length (20-m) fiber cavity is lower than 5 mW, and high conversion efficiencies (up to 60%) are obtained at any pump power up to ~200 mW . Using the single-mode Stokes beam as a seed for the stimulated Brillouin scattering process allows up to 40-dB optical carrier depletion with almost no added noise for an optically carried microwave signal at 6 GHz. In addition, using this resonator, we provide evidence of generation of high-spectral-purity beatnotes.
© 2003 Optical Society of America
(060.4370) Fiber optics and optical communications : Nonlinear optics, fibers
(140.3510) Lasers and laser optics : Lasers, fiber
(190.4360) Nonlinear optics : Nonlinear optics, devices
(190.5890) Nonlinear optics : Scattering, stimulated
S. Norcia, S. Tonda-Goldstein, D. Dolfi, J.-P. Huignard, and R. Frey, "Efficient single-mode Brillouin fiber laser for low-noise optical carrier reduction of microwave signals," Opt. Lett. 28, 1888-1890 (2003)