Apple Inc.
Low-temperature hermetic sealing for diffractive optical element stacks

Abstract:

A method for producing an optical apparatus includes providing a pair of glass wafers. One or more diffractive optical elements (DOEs) are formed on one or more of the glass wafers. A spacer is positioned between the glass wafers so as to define a cavity containing the DOEs, and a hermetic seal that bonds the glass wafers together and seals the cavity is formed.