Optical apparatus which uses a virtually imaged phased array to produce chromatic dispersion

Abstract

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 distinguishable 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.

1 - 109 . (canceled)  
   
   
       110 . An apparatus comprising: 
 a virtually imaged phased array (VIPA) generator receiving a line focused input light at a respective wavelength and producing a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the VIPA generator having a corresponding angular dispersion direction and the input light having an associated loss curve;    a reflecting surface; and    a lens or mirror focusing the output light traveling from the VIPA generator onto the reflecting surface so that the reflecting surface reflects the output light, the reflected light being directed by the said lens or mirror back to the VIPA generator, wherein the reflecting surface is patterned to flatten the loss curve.