Fiber optic switch employing moveable structure interaction with the evanescent field of a cladding-removed fiber

A wavelength selective fiber optic switch, comprising:

• an optical fiber having a fiber core and a cladding,
• a portion of the cladding being removed to define a window facilitating access to the evanescent field present when optical power is propagating through the optical fiber;
• a grating configured to define a grating period corresponding to an optical wavelength;
• an adjustable positioning fixture configured to hold the grating proximate to the window and operable to change the relative spacing of the fiber core and grating, between:
• a first position in which the grating is held proximate to the fiber core and substantially interacts with the evanescent field, and
• a second position in which the grating is held apart from the fiber core and does not substantially interact with the evanescent field,
• the cladding-removed portion of the fiber core and the grating cooperatively defining a switch that operates:
• in said first position, to substantially impede propagating optical power in the optical fiber at the Bragg wavelength;
• and
• in said second position, to permit propagating optical power in the optical fiber at the optical wavelength and all other wavelengths naturally supported by the unperturbed optical fiber.