Tuning, attenuating, and switching by controlled flexure of long-period fiber gratings

Azimuthal variations in the refractive index that are inherent in CO(2) -laser-induced long-period fiber gratings (LPFG's) coupled to small controlled flexure of the LPFG produce a wide variety of transmission characteristics as a function of LPFG curvature. The particularly useful cases of (1) wavelength tuning at a constant attenuation and (2) variable attenuation (switching) at a constant wavelength are demonstrated by flexing of LPFG's that have been appropriately axially rotationally oriented relative to the plane of curvature.