Backside binary grated lens coupled to front side waveguide

Patent metadata

Field	Value
Publication number	US-9910223-B2
Application number	US-201715439070-A
Country	US
Kind code	B2
Filing date	Feb 22, 2017
Priority date	Jun 30, 2015
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

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 converges a width of the light and includes an insulator layer with material filled in trenches of the insulator layer, and
the front side waveguide is provided on a buried insulator layer.

2. The structure of claim 1 , wherein the material filled in the trenches of the insulator layer includes a silicon nitride material.

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 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.

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;
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, wherein the waveguide is provided on a buried insulator layer.

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.

14. A method comprising:
providing a diffractive lens on a backside of a wafer;
connecting a waveguide to a front side of the wafer; and
providing a coupler including a polysilicon material and connecting the waveguide to the wafer,
wherein:
the diffractive lens configured to receive light and focus the light to the waveguide connected to the front side of the wafer,
the coupler receives light redirected by the insulator layer and the material filled in the trenches, and
the connecting the waveguide to the wafer waveguide comprises providing the waveguide on a buried insulator layer.

15. The method of claim 14 , wherein the providing the diffractive lens on the backside of the wafer comprises:
etching a plurality of trenches; and
filling the plurality of trenches with a material having a substantially different index of refraction than the insulator layer.

16. The method of claim 15 , wherein the plurality of trenches are filled with a silicon nitride material.

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

• G02B6/4206

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

• G02B6/29304

  operating by diffraction, e.g. grating (G02B6/29301 takes precedence; spectrometers using gratings G01J3/18) · 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