Vertically-tapered optical waveguide and optical spot transformer formed therefrom
First Claim
1. An optical waveguide formed on a substrate and comprising a waveguide core sandwiched between an upper cladding layer and a lower cladding layer, with the lower cladding layer being patterned to form a mesa structure having a width that varies with distance along at least a portion of the length of the optical waveguide, and with the thickness of the waveguide core varying in proportion to the width of the mesa structure.
3 Assignments
0 Petitions
Accused Products
Abstract
An optical waveguide is disclosed in which a section of the waveguide core is vertically tapered during formation by spin coating by controlling the width of an underlying mesa structure. The optical waveguide can be formed from spin-coatable materials such as polymers, sol-gels and spin-on glasses. The vertically-tapered waveguide section can be used to provide a vertical expansion of an optical mode of light within the optical waveguide. A laterally-tapered section can be added adjacent to the vertically-tapered section to provide for a lateral expansion of the optical mode, thereby forming an optical spot-size transformer for efficient coupling of light between the optical waveguide and a single-mode optical fiber. Such a spot-size transformer can also be added to a III-V semiconductor device by post processing.
-
Citations
31 Claims
- 1. An optical waveguide formed on a substrate and comprising a waveguide core sandwiched between an upper cladding layer and a lower cladding layer, with the lower cladding layer being patterned to form a mesa structure having a width that varies with distance along at least a portion of the length of the optical waveguide, and with the thickness of the waveguide core varying in proportion to the width of the mesa structure.
-
20. An optical spot-size transformer for coupling light between an optical fiber and an optical waveguide formed on a substrate, comprising:
-
(a) a first section of the optical waveguide located proximate to the optical fiber for altering a lateral dimension of an optical mode of the light, with the first section further comprising a waveguide core sandwiched between an upper cladding layer and a mesa structure formed in a lower cladding layer, with the waveguide core and the mesa structure both being substantially uniform in width and height, and with the upper cladding layer having a substantially uniform height and a nonuniform width that increases with distance away from the optical fiber; and
(b) a second section of the optical waveguide located distal to the optical fiber for altering a vertical dimension of the optical mode of the light, with the second section further comprising the waveguide core sandwiched between the upper cladding layer and the mesa structure, and with the height of the waveguide core and the width of the mesa structure both increasing with distance away from the optical fiber. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27)
-
-
28. A method for forming a vertically-tapered optical waveguide on a substrate, comprising steps for:
-
(a) forming a lower cladding layer on the substrate, and patterning the lower cladding layer to form a mesa structure having a mesa width that varies with distance along at least a part of the length of the optical waveguide;
(b) forming a waveguide core on the mesa structure by depositing a spin-coatable material over the mesa structure with a thickness of the waveguide core at any point along the length of the optical waveguide being defined by the width of the mesa structure at that point; and
(c) forming an upper cladding layer above the waveguide core. - View Dependent Claims (29, 30, 31)
-
Specification