DIFFRACTIVE PHOTO MASKS AND METHODS OF USING AND FABRICATING THE SAME
An exemplary embodiment of the present invention provides a diffractive photo-mask comprising a body element, a plurality of interference/image-forming hologram gratings, and a zero-order beam blocking element. The plurality of interference/image-forming hologram gratings can be located on or in the body element. The plurality of interference/image-forming hologram gratings are configured to diffract a light beam to produce one or more functional elements surrounded by a high-spatial-frequency periodic optical-intensity distribution at a substrate plane when the light beam is incident upon the diffractive photo-mask. The zero-order beam blocking element is configured to block zero-order diffracted beams when the light beam is incident upon the diffractive photo-mask
1 . A diffractive photo-mask, comprising:
a body element;
a plurality of interference/image-forming hologram gratings located on or in the body element and configured to diffract a light beam to produce one or more functional elements surrounded by a high-spatial-frequency periodic optical-intensity distribution at a substrate plane, when the light beam is incident upon the diffractive photo-mask; and
a zero-order beam blocking element configured to block zero-order diffracted beams when the light beam is incident upon the diffractive photo-mask.
2 . The diffractive photo-mask of claim 1 , wherein the diffractive photo-mask is located proximate to a surface of a photosensitive material.
3 . The diffractive photo-mask of claim 1 , wherein the plurality of interference/image-forming hologram gratings are located proximate to a top surface of the body element.
4 . The diffractive photo-mask of claim 1 , further comprising a transparent material configured to place the diffractive photo-mask in physical contact with a photosensitive material at the substrate plane.
5 . The diffractive photo-mask of claim 1 , wherein the plurality of interference/image-forming hologram gratings comprise at least one high-efficiency volume grating.
6 . The diffractive photo-mask of claim 1 , wherein the plurality of interference/image-forming hologram gratings comprise at least one material having an index of refraction that is different than an index of refraction of the body element.
7 . A method of fabricating a high-spatial frequency periodic structure comprising:
directing a light beam to be incident upon a diffractive photo-mask, such that the diffractive photo-mask diffracts the light beam to produce one or more functional elements surrounded by a high-spatial-frequency periodic optical-intensity distribution at a substrate plane.
8 . The method of fabricating a high-spatial frequency periodic structure of claim 7 , further comprising placing the diffractive photo-mask proximate a surface of a photosensitive material, such that the photosensitive material is located proximate to the substrate plane.
9 . The method of fabricating a high-spatial frequency periodic structure of claim 7 , wherein the diffractive photo-mask comprises:
a body element;
a plurality of interference/image-forming hologram gratings located on or in the body element and configured to diffract the light beam to produce one or more functional elements surrounded by a high-spatial-frequency periodic optical-intensity distribution at a substrate plane; and
a zero-order beam blocking element configured to block zero-order diffracted beams.
10 . The method of fabricating a high-spatial frequency periodic structure of claim 9 , wherein the plurality of interference/image-forming hologram gratings are located proximate to a top surface of the body element.
11 . The method of fabricating a high-spatial frequency periodic structure of claim 9 , wherein the diffractive photo-mask further comprises a transparent material placing the diffractive photo-mask in physical contact with the photosensitive material at the substrate plane.
12 . The method of fabricating a high-spatial frequency periodic structure of claim 9 , wherein the plurality of interference/image-forming hologram gratings comprise at least one high-efficiency volume grating.
13 . The method of fabricating a high-spatial frequency periodic structure of claim 9 , wherein the plurality of interference/image-forming hologram gratings comprise at least one material having an index of refraction that is different than an index of refraction of the body element.
14 . A method of fabricating a diffractive photo-mask, the method comprising:
transmitting a zero-order reference light beam that interferes with a plurality of interference/image-forming light beams to interferometrically record a plurality of interference/image-forming hologram gratings in a photo-mask recording material.
15 . The method of fabricating a diffractive photo-mask of claim 14 , further comprising monitoring and adjusting an alignment of a functional-element image.
16 . The method of fabricating a diffractive photo-mask of claim 15 , wherein adjusting the alignment of the functional element image incorporates automatic feedback control technology.
17 . The method of fabricating a diffractive photo-mask of claim 14 , wherein the plurality of interference/image-forming hologram gratings are formed by a scanned writing method.
18 . The method of fabricating a diffractive photo-mask of claim 14 , wherein the interference/image-forming hologram gratings are configured to diffract a beam of light to produce a functional-element optical-intensity distribution.