Abstract: A method for creating gradient optical properties within a substrate is disclosed herein. More specifically, the present invention teaches a method whereby a material disposed on a substrate is patterned in three dimensions such that the thickness and diffusivity properties of the material can be used to regulate the diffusion of ions into the substrate. An example is given in which ions, injected into a substrate through an ion exchange process, alter the refractive index within the substrate in a pre-selected fashion to form a gradient refractive index lens.

Abstract: A method of controlling a substrate etching process includes disposing a bottom surface or a top surface of a substrate adjacent to volume of etching fluid to produce an etchant-substrate interface and heating the etchant-substrate interface via spatially controlled electromagnetic radiation. The method also includes transmitting a monitoring beam through the substrate, the substrate and volume of etching fluid being at least partially transparent at the wavelength range of the monitoring beam and measuring a property of the substrate surface during the substrate etching process via the monitoring beam to produce a real-time measured property for the substrate. A corresponding etching system and computer-program product is also disclosed herein.