Switchable and reconfigurable optical grating devices and methods for making them

A reconfigurable optical fiber grating device comprising:

• a length of optical fiber having an outer circumference and a diameter and
• a plurality of spaced-apart conductive element pairs on the outer circumference of the optical fiber, wherein each conductive element pair comprises a first conductive element on one side of the diameter and a second conductive element on the other side of the diameter, the plurality of conductive element pairs defining a grating region along said fiber and within said fiber an actuable component responsive to an electrical signal applied to each conductive element pair for producing a respective localized perturbation in the optical properties of the fiber;
• each conductive element pair subject to the selective application of voltage to produce a respective localized perturbation of the fiber and said plurality of conductive element pairs positioned and spaced for producing a sequence of localized perturbations forming an optical grating wherein the wavelength response of the optical grating can be controllably altered between wavelengths by selective application of voltage to said conductive element pairs.