Apparatus and method of fabricating a compensating element for wavefront correction using spatially localized curing of resin mixtures
View Patent ↗An optical wavefront correction plate incorporates a unique, three-dimensional spatial retardation distribution utilizing the index of refraction change of resin mixture in its cured state. The optical wave plate comprises a pair of transparent plates, containing a layer of a monomers and polymerization initiators, such as resin mixture. This resin mixture exhibits a variable index of refraction as a function of the extent of its curing. Curing of the resin mixture may be made by exposure to light, such as ultraviolet light, and may be varied across and through the surface of the resin mixture to create a particular and unique three-dimensional wavefront retardation profile. The optical wave plate provides improved performance in large area mirrors, lenses, telescopes, microscopes, and ophthalmic diagnostic systems.
1. A method for manufacturing a correcting element having at least one transparent element, and a layer of curable, refractive index changing material adjacent to the at least one transparent element, comprising:
obtaining a three-dimensional index of refraction profile;
focusing a radiation beam on a first location within the material layer to establish a first curing volume within the material layer; and
refocusing the radiation beam on one or more subsequent positions within the material layer to establish one or more additional curing volumes, wherein the first curing volume and the subsequent curing volumes collectively establish the three-dimensional index of refraction profile, wherein at least two curing volumes occupy different depth positions within the material layer.
2. The method of claim 1 , wherein the first curing volume and the subsequent curing volumes are located in two or more curing layers having different depths within the layer of material.
3. The method of claim 1 , further comprising:
determining aberrations in a wavefront; and
determining the three dimensional index of refraction profile to compensate for at least some of the aberrations.
4. The method of claim 1 , wherein forming the first curing volume and the subsequent curing volumes further comprises exposing the material layer to a light beam having a wavelength suitable for curing the material layer.
5. The method of claim 1 , further comprising stabilizing the curing of material layer after the profile has been established, the act including removing uncured material from the material layer to establish at least one cavity and undertaking at least one of:
(1) refilling the cavity with an optically stable fluid which exhibits no refractive index change when exposed to radiation;
(2) refilling the cavity with the same or similar material without any photo-initiator;
(3) refilling the cavity with material containing a curing inhibitor;
(4) refilling the cavity with another type of material having a desirable curing characteristic and with a predetermined index of refraction such that the final index of refraction profile in the wave plate is reached when all the material in the cavity is substantially cured;
(5) adhering cured material to the at least one transparent element; and
(6) applying highly absorptive or highly reflective coatings on the surface of the at least one transparent element to protect the material layer from exposure to at least some light.
6. The method of claim 1 , wherein the curing volumes are exposed to a focused light beam sequentially such that curing volumes positioned further from a source of said focused light beam are exposed prior to curing volumes positioned closer to said source of said focused light beam.
7. The method of claim 1 , wherein the first curing volume and at least one subsequent curing volume occupy adjacent locations in a single curing layer within the layer of resin mixture.
8. The method of claim 7 , wherein the first curing volume and the at least one subsequent curing volume occupy overlapping positions in the single curing layer such that the distance between center portions of the first curing volume and the at least one subsequent curing volume is less than a diameter of a beam waist of the first curing volume or the at least one subsequent curing volume.