Backside binary grated lens coupled to front side waveguide

Patent metadata

Field	Value
Publication number	US-10605992-B2
Application number	US-201715798581-A
Country	US
Kind code	B2
Filing date	Oct 31, 2017
Priority date	Jun 30, 2015
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

A wafer structure includes a diffractive lens disposed on a backside of a wafer and coupled to a front side waveguide, the diffractive lens being configured to receive light and focus the light to the front side waveguide.

First claim

What is claimed:

1. A wafer structure comprising:
a diffractive lens disposed on a backside of a wafer and coupled to a front side waveguide, the diffractive lens being configured to receive light and focus the light to the front side waveguide, wherein the diffractive lens comprises:
an insulator layer comprising trenches that each extend from a first surface of the insulator layer to a second surface of the insulator layer, the second surface of the insulator layer contacting the backside of the wafer; and
segments in the trenches in the insulator layer, wherein each of the segments comprises an insulator material with a surface that is co-planar with the first surface of the insulator layer.

2. The structure of claim 1 , wherein the insulator material of the segments is different than an insulator material of the insulator layer.

3. The structure of claim 1 , wherein the lens is a binary diffractive lens.

4. The structure of claim 1 , further comprising a coupler connecting the front side waveguide to the wafer, wherein the coupler receives the light and transmits the light to the waveguide.

5. The structure of claim 4 , wherein the coupler includes a polysilicon material.

6. The structure of claim 4 , wherein the coupler is a spacer coupled to the front side waveguide and has a substantially 90-degree curved elbow shape.

7. The structure of claim 6 , wherein:
the front side waveguide includes a single crystalline silicon material, and the coupler is thicker than the front side waveguide, wherein the curved elbow shape of the coupler redirects the light approximately 90 degrees from a point from where the light is received by the coupler at a front side of the wafer to a point where the light enters the front side waveguide, and
the coupler includes a polysilicon material.

8. The structure of claim 1 , wherein the light is received from an optical fiber.

9. A structure comprising:
a lens structure on a first side of a wafer, the lens structure comprising a material which fills trenches of a predefined pattern and which has a different index of refraction as the material in which the trenches are formed, wherein the material that fills the trenches forms segments, and each of the segments has a first surface that contacts the first side of the wafer and a second surface that is coplanar with a surface of the material in which the trenches are formed;
a coupler provided on a second side of the wafer and aligned with the light provided from the lens structure; and
a waveguide coupled to the coupler.

10. The structure of claim 9 , wherein the material includes a silicon nitride material.

11. The structure of claim 9 , wherein the coupler includes a polysilicon material.

12. The structure of claim 9 , wherein the first side is a backside and the second side is a front side.

13. The structure of claim 9 , wherein the light is received by the lens from an optical fiber.

Assignees

• IBM

Inventors

• Amoah Yoba
• Brown Brennan J
• Ellis-Monaghan John J
• Kreider Ashleigh R

Classifications

• G02B6/305

  and having an integrated mode-size expanding section, e.g. tapered waveguide · CPC title

• G02B6/30

  for use between fibre and thin-film device · CPC title

• G02B6/34

  utilising prism or grating {(G02B6/293 takes precedence)} · CPC title

• G02B6/4206

  Optical features (G02B6/4207, G02B6/421 take precedence) · CPC title

• G02B6/352

  the reflective optical element having a shaped reflective surface, e.g. a reflective element comprising several reflective surfaces or facets that function together · CPC title