A novel shape-adjustable narrowband optical filter utilizing stimulated Brillouin scattering in an optical fiber is proposed and demonstrated. In this scheme, binary-phase-shift-keying modulation is applied to the pump wave to broaden and shape the Brillouin gain spectrum. By choosing an appropriate modulation data pattern, we realized a flat-top steep-cutoff optical bandpass filter with a 3-dB bandwidth of 1.5 GHz and a 10-dB bandwidth of 2 GHz is realized. In addition, a tunable optical notch filter is also realized by deamplification of the anti-Stokes wave.
© 2002 Optical Society of America
(060.2330) Fiber optics and optical communications : Fiber optics communications
(060.2340) Fiber optics and optical communications : Fiber optics components
(060.4370) Fiber optics and optical communications : Nonlinear optics, fibers
(230.4320) Optical devices : Nonlinear optical devices
(290.5900) Scattering : Scattering, stimulated Brillouin
Takuo Tanemura, Yuichi Takushima, and Kazuro Kikuchi, "Narrowband optical filter, with a variable transmission spectrum, using stimulated Brillouin scattering in optical fiber," Opt. Lett. 27, 1552-1554 (2002)