Tunable dispersion compensator and optical system comprising same

An article comprising a dispersion compensator device, the compensator device comprising:

• a length of waveguide including a grating region having a plurality of spaced-apart grating elements;
• a body disposed adjacent the length of waveguide and attached to the waveguide proximal the grating region, the body having a gradient in its structure, dimensions, chemistry, or porosity to define a gradient-generating body;
• a fixed substrate having a point of attachment to at least one of the body or the length of waveguide;
• and
• a component for moving the body along the length of the waveguide in a longitudinal direction either away from or toward the fixed substrate, wherein when the component moves the body along the length of the waveguide, an elastic strain is induced in the body and a non-uniform strain is imposed on the length of the waveguide to non-uniformly adjust the spacings between the grating elements to alter the dispersion compensating characteristics of the waveguide.