Method for manufacturing an optical device

A method of manufacturing an optical device, the method comprising:

• engraving a first trench in a glass plate;
• engraving a second trench in the glass plate obliquely relative to a direction normal to an upper surface of the glass plate, wherein the second trench crosses the first trench, and wherein the first trench has an open end in a first wall of the second trench;
• treating the glass plate and surfaces of the first and second trenches with hydrofluoric acid;
• depositing a resin layer onto the glass plate and surfaces of the first and second trenches;
• removing a portion of the resin layer from a second wall of the second trench opposite the first wall;
• depositing a metal layer over remaining portions of the resin layer and second wall of the second trench;
• removing all remaining portions of the resin layer and any portions of the metal layer covering the resin layer, leaving a portion of the metal layer on the second wall of the second trench to form a mirror;
• filling the first trench with a material having a refractive index different from that of the glass plate to form a waveguide comprising a first major outer surface and a second major outer surface that is parallel to the first major outer surface, wherein the waveguide is separated from the mirror by a distance of less than 50 μm;
• and
• depositing an encapsulation layer over the glass plate, the waveguide, and the second trench, wherein the second trench is filled with the encapsulation layer so that a portion of the encapsulation layer in the second trench separates the waveguide from the mirror, wherein, after the depositing, the first wall of the second trench and a bottom surface of the second trench are covered with a portion of the encapsulation layer and the second wall of the second trench is covered with the mirror, wherein the optical device comprises an optical path between the waveguide and the mirror through the portion of the encapsulation layer.

A method of manufacturing an optical device, the method comprising:

• forming a first trench and a second trench in a glass plate, the second trench comprising a first wall and a second wall opposite the first wall, the first and second walls being inclined relative to a vertical direction normal to an upper surface of the glass plate, wherein the second trench intersects the first trench, and wherein the first trench has an open end in the first wall of the second trench;
• covering the first wall and the second wall with a resin layer;
• removing a portion of the resin layer from the second wall of the second trench;
• forming a mirror covering the second wall;
• filling the first trench with a material having a refractive index different from that of the glass plate to form a waveguide comprising a first major outer surface and a second major outer surface that is parallel to the first major outer surface;
• and
• depositing an encapsulation layer over the glass plate, waveguide, and the second trench, wherein the encapsulation layer covers all of an upper surface of the waveguide and all of an upper surface of the glass plate, wherein the second trench is filled with the encapsulation layer so that a portion of the encapsulation layer in the second trench separates the waveguide from the mirror, wherein the encapsulation layer filling the second trench and covering all of the upper surface of the waveguide and all of the upper surface of the glass plate has a refractive index that is smaller from the waveguide and the glass plate, wherein the optical device comprises an optical path between the waveguide and the mirror through the portion of the encapsulation layer.