Photo detector and method for producing photo detector
AssigneeSumitomo Electric Industries, Ltd.
InventorsTakuya Okimoto, Hideki Yagi
Life of this patent
Estimating the term…
Abstract
A photo detector includes a variable optical attenuator provided on a substrate, an optical 90-degree hybrid device provided on the substrate, and a plurality of photodiodes provided on the substrate. The plurality of photodiodes are optically coupled to the variable optical attenuator via the optical 90-degree hybrid device. The variable optical attenuator includes an optical waveguide disposed on the substrate, a heater configured to heat the optical waveguide, and an insulating layer at least partially disposed between the substrate and the optical waveguide.
Claims17
A photo detector comprising:
- a variable optical attenuator provided on a substrate;
- an optical 90-degree hybrid device provided on the substrate;
- and
- a plurality of photodiodes provided on the substrate,
- wherein the plurality of photodiodes are optically coupled to the variable optical attenuator via the optical 90-degree hybrid device,
- wherein the variable optical attenuator includes an optical waveguide provided on the substrate, a heater configured to heat the optical waveguide, and an insulating layer at least partially disposed between the substrate and the optical waveguide,
- wherein the insulating layer includes a semiconductor portion and a void portion, and
- wherein the semiconductor portion and the void portion are alternately arranged along the optical waveguide.
A method for producing a photo detector including a variable optical attenuator provided on a substrate, an optical 90-degree hybrid device provided on the substrate, and a plurality of photodiodes provided on the substrate, the plurality of photodiodes being optically coupled to the variable optical attenuator via the optical 90-degree hybrid device, the method comprising:
- forming a first semiconductor layer on an area of a main surface of the substrate for forming the variable optical attenuator;
- forming a second semiconductor layer on the first semiconductor layer, the second semiconductor layer providing an optical waveguide for the variable optical attenuator;
- and
- forming a heater configured to heat the optical waveguide on the second semiconductor layer,
- wherein, between the forming of the second insulating layer and the forming of the heater, the first semiconductor layer is etched to provide an insulating layer including at least one semiconductor portion and at least one void portion, each semiconductor portion and each void portion being arranged alternately along the optical waveguide.
Dependencies are inferred from the claim text.