Patent ID: 8901190

Claim:
A method for modifying the refractive index of an optical, hydrogel polymeric material, the method comprising irradiating predetermined regions of the optical, hydrogel polymeric material with a laser to form refractive structures, wherein the refractive structures exhibit a change in refractive index, and exhibit little or no scattering loss, with respect to the non-irradiated regions of the material, and the optical, polymeric material comprises a photosensitizer to enhance the photoefficiency of two photon absorption by the polymeric material to form the refractive structures, wherein the photosensitizer permits one to irradiate the predetermined regions using a scan rate that is at least fifty times greater than a scan rate without the photosensitizer in the material, or permits one to set an average power of the laser to a value that is at least two times less than an average laser power without the photosensitizer in the material, yet provide similar refractive structures in terms of the observed change in refractive index of the irradiated regions; wherein the optical, hydrogel polymeric material has a water content from 15% to 60% and comprises at least three monomeric components: a first monomeric component is present in an amount of at least 60% by weight, and its homopolymer will have a refractive index of at least 1.50; a second monomeric component is present in an amount from 3% to 20% by weight, and a hydrophilic component present in an amount from 2% to 30% by weight.