Zero-Alignment Method for Tunable Fabrication of Three-Dimensional Photonic Crystals by Multiple-Exposure Laser Interference Using Diffraction Gratings Patterned on a Single Mask (Jointly owned with the Army)

A method for fabricatingthree-dimensional photonic crystal structures includes providing alayer of photosensitive material; introducing a laser beams into the material;reintroducing the laser beams into the photosensitive material during a second exposure; combiningresults from at least the first and second exposures to produce athree-dimensionally periodic pattern in the photosensitive material. A relatedsystem includes a laser source; a grating array having a plurality of diffractiongratings located thereon; a mask plate located on a photoresist layer andarranged in registration with the grating array; a rotating shutter arrangedbetween the grating array and the laser source, said rotating shutter beingsuitable for periodically blocking light from the laser source; wherein each ofthe diffraction gratings is positioned and oriented so as to converge allfirst-order diffracted spots to a common point lying in a plane of a back sideof the mask plate.

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