Patent ID: 6334018
Filing Date: 2001-12-25
Classification: C03C,G02B

Abstract:
A method of providing an optical element with a periodically spatially varying chemical composition, comprising the steps ofa) diffusing at least one mobile substance in the optical element;b) periodically inducing at least one chemical reaction between the diffused substance or substances and the optical element, by delivering energy by electromagnetic radiation via optical writing or by a predetermined temperature increase;c) changing the temperature of the optical element to a predetermined temperature level so that said diffused substance or substances that has not chemically reacted in said step b) diffuses out of the optical element; andd) heating the optical element to a predetermined temperature higher than employed in said step c) by changing the energy supply to complete a reaction to diffuse out substances from the optical element to obtain a stable chemically varying optical element having periodically varying optical properties.