A method is presented for constructing a fiber-optic loop mirror whose reflectivity is tunable even though a fixed-ratio directional coupler is used. The tunability is polarization and wavelength independent and depends only on the geometry of the fiber-tuning element. This loop mirror can be used to transfer energy from one channel to another in a controllable way. We experimentally demonstrate the tunable reflectivity and present some experimental investigations.
© 2000 Optical Society of America
(060.2310) Fiber optics and optical communications : Fiber optics
(260.1440) Physical optics : Birefringence
(260.5430) Physical optics : Polarization
(350.1370) Other areas of optics : Berry's phase
P. Senthilkumaran, Graham Thursby, and Brian Culshaw, "Fiber-optic tunable loop mirror using Berry's geometric phase," Opt. Lett. 25, 533-535 (2000)