An optical apparatus for producing chromatic dispersion. The apparatus includes
a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA
generator receives an input light at a respective wavelength and produces a corresponding
collimated output light traveling from the VIPA generator in a direction determined
by the wavelength of the input light, the output light thereby being spatially
distiguishable from an output light produced for an input light at a different
wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses
the output light traveling from the VIPA generator onto the mirror so that the
mirror reflects the output light. The reflected light is directed by the lens back
to the VIPA generator. In this manner, the apparatus provides chromatic dispersion
to the input light. The modified cone shape of the mirror can be designed so that
the apparatus provides a uniform chromatic dispersion to light in the same channel
of a wavelength division multiplexed light. The mirror can be moved in a direction
perpendicular to an angular dispersion direction of the VIPA generator, to change
the amount of chromatic dispersion provided to the input light.
