Direct-bonded lamination for improved image clarity in optical devices

An apparatus, comprising:

• a first optically transparent substrate including a first flat surface;
• a second optically transparent substrate including a second flat surface;
• one or more reflective coatings on at least one of the first flat surface or the second flat surface, wherein the one or more reflective coatings is at least partially reflective;
• and
• a direct bond between a material of the first flat surface of the first optically transparent substrate and a material of the second flat surface of the second optically transparent substrate,
• wherein the direct bond comprises a refractory interface between the first flat surface and the second flat surface, the direct bond comprising the refractory interface having a same coefficient of thermal expansion as the first flat surface or the second flat surface, and the direct bond comprising the refractory interface having a high resistance to heat and a high resistance to elevated temperatures, and
• wherein the apparatus has an oblique shape with respect to a perpendicular of the one or more reflective coatings.

A method of forming a mirrored optical waveguide, the method comprising:

• creating a stack comprising a first optically transparent substrate and a second optically transparent substrate, the creating comprising:
• planarizing a first surface of the first optically transparent substrate;
• planarizing a second surface of the second optically transparent substrate;
• depositing one or more reflective coatings on at least one of the first surface or the second surface, wherein the one or more reflective coatings is at least partially reflective;
• covering the one or more reflective coatings with a layer of a silicon oxide, silicon nitride, silicon carbonitride or silicon oxynitride;
• placing the first surface of the first optically transparent substrate and the second surface of the second optically transparent substrate in contact with each other for forming direct bonds between the first surface and the second surface at room temperature;
• and
• forming spontaneous chemical bonds between respective layers of the silicon oxide, silicon nitride, silicon carbonitride or silicon oxynitride on the first optically transparent substrate and the second optically transparent substrate;
• and
• dicing the stack at an oblique angle to a perpendicular of the one or more reflective coatings.