Cantilever beam waveguide for silicon photonics device

Patent metadata

Field	Value
Publication number	US-11320718-B1
Application number	US-202016998816-A
Country	US
Kind code	B1
Filing date	Aug 20, 2020
Priority date	Sep 26, 2019
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

A cantilever beam waveguide for a silicon photonics device may be formed in a device layer (e.g., a silicon device layer) of a silicon photonics device (e.g., a chip) and may be configured to bend to align the cantilever beam waveguide or a portion thereof with one or more additional components of the silicon photonics device or another device, including output couplers, optical sources, and waveguides.

First claim

What is claimed is:

1. A silicon photonics device comprising:
a silicon support layer;
an oxide layer disposed above the silicon support layer and defining a gap;
a silicon device layer disposed above the oxide layer and comprising:
a first electrode;
a second electrode; and
a cantilever beam waveguide positioned at least partially over the gap and between the first electrode and the second electrode, the cantilever beam waveguide configured to capacitively couple to the first electrode and the second electrode; and

an output coupler formed on or bonded to the silicon device layer and configured to direct at least a portion of light propagating through the cantilever beam waveguide out of the silicon photonics device; wherein:
the first electrode and the second electrode are configured to receive voltage signals that cause the cantilever beam waveguide to bend to selectively optically couple the cantilever beam waveguide with one or more additional components of the silicon photonics device.

2. The silicon photonics device of claim 1 , wherein:
the one or more additional components comprise an array of waveguides formed in the silicon device layer;
in a first bending configuration of the cantilever beam waveguide, the cantilever beam waveguide directs light into a first waveguide of the array of waveguides; and
in a second bending configuration of the cantilever beam waveguide, the cantilever beam waveguide directs light into a second waveguide of the array of waveguides.

3. The silicon photonics device of claim 1 , wherein:
the first electrode defines a first comb drive formed in the silicon device layer;
the second electrode defines a second comb drive formed in the silicon device layer; and
the first and second comb drives are configured to cause the cantilever beam waveguide to oscillate at a resonant frequency of the cantilever beam waveguide.

4. The silicon photonics device of claim 1 , wherein:
the voltage signals comprise:
a first alternating-current voltage signal applied to the first electrode and having a frequency that is equal to a resonant frequency of the cantilever beam waveguide; and
a second alternating-current voltage signal applied to the second electrode and having the frequency, the second alternating-current voltage signal 180 degrees out of phase with the first alternating-current voltage signal; and

the first alternating-current voltage signal and the second alternating-current voltage signal cause the cantilever beam waveguide to oscillate at the resonant frequency.

5. The silicon photonics device of claim 1 , wherein:
the silicon device layer defines a first surface facing the oxide layer and a second surface opposite the first surface; and
the silicon photonics device further comprises:
a first contact disposed on the second surface of the silicon device layer in the first electrode and configured to electrically couple the first electrode to a processing unit configured to cause the voltage signals to be generated;
a second contact disposed on the second surface of the silicon device layer in the second electrode and configured to electrically couple the second electrode to the processing unit; and
a third contact disposed on the second surface of the silicon device layer and configured to electrically couple the cantilever beam waveguide to the processing unit.

6. The silicon photonics device of claim 1 , wherein the output coupler is formed on or bonded to a surface of the silicon device layer.

7. The silicon photonics device of claim 6 , wherein the output coupler is formed on an angled surface of the cantilever beam waveguide.

8. The silicon photonics device of claim 6 , further comprising a lens positioned between the cantilever beam waveguide and the output coupler and configured to focus light toward the output coupler.

9. The silicon photonics device of claim 1 , wherein a cantilever portion of the cantilever beam waveguide has a length between 200 and 500 microns and a width between 0.1 and 0.4 microns.

10. A silicon photonics device for an electronic device, comprising:
a cantilever beam waveguide formed in a silicon device layer and configured to optically couple with a component of the silicon photonics device;
a first comb drive formed in the silicon device layer and coupled to a first side of the cantilever beam waveguide;
a second comb drive formed in the silicon device layer and coupled to a second side of the cantilever beam waveguide opposite the first side; and
an output coupler formed on or bonded to the silicon device layer and configured to direct at least a portion of light propagating through the cantilever beam waveguide out of the silicon photonics device; wherein:
the first comb drive and the second comb drive are configured to receive voltage signals to actuate the first comb drive and the second comb drive to cause the cantilever beam waveguide to oscillate at a resonant frequency of the cantilever beam waveguide; and
in a first bending configuration of the cantilever beam waveguide during oscillation, the cantilever beam waveguide is optically coupled to the component of the silicon photonics device; and
in a second bending configuration of the cantilever beam waveguide during oscillation, the cantilever beam waveguide is not optically coupled to the component of the silicon photonics device.

11. The silicon photonics device of claim 10 , wherein:
the component is a first waveguide of an array of waveguides comprising the first waveguide and a second waveguide; and
in the second bending configuration, the cantilever beam waveguide is optically coupled to the second waveguide.

12. The silicon photonics device of claim 10 , wherein:
the component is gain component comprising a first mirror;
the cantilever beam waveguide comprises a second mirror configured to align with the first mirror to define a laser cavity; and
oscillating the cantilever beam waveguide modulates a beam of light produced in the laser cavity between an off state and an on state.

13. The silicon photonics device of claim 12 , wherein the gain component comprises a III-V semiconductor material.

14. The silicon photonics device of claim 10 , wherein the first comb drive and the second comb drive are radial comb drives.

15. An electronic device comprising:
a silicon photonics device comprising:
a first electrode;
a second electrode;
a cantilever beam waveguide positioned between the first electrode and the second electrode and configured to bend to selectively align with one or more additional components of the silicon photonics device;

an output coupled to the silicon photonics device and configured to direct at least a portion of light propagating through the cantilever beam waveguide out of the silicon photonics device; and
a processing unit configured to cause voltage signals to be applied to the first electrode and the second electrode to cause the cantilever beam waveguide to bend.

16. The electronic device of claim 15 , wherein:
the electronic device is a wearable electronic device; and
the silicon photonics device is included in a PPG sensor of the wearable electronic device.

17. The electronic device of claim 15 , wherein the processing unit is configured to use the silicon photonics device to perform a distance measurement.

18. The electronic device of claim 15 , wherein the voltage signals cause the cantilever beam waveguide to oscillate.

19. The electronic device of claim 15 , wherein:
the one or more additional components of the sil

Assignees

• Apple Inc

Inventors

• MAHMOUD Mohamed
• Bismuto Alfredo
• Arbore Mark Alan

Classifications

• G02F1/313 Primary

  in an optical waveguide structure · CPC title

• G02F2203/24

  beam steering · CPC title

• G02B6/3502

  involving direct waveguide displacement, e.g. cantilever type waveguide displacement involving waveguide bending, or displacing an interposed waveguide between stationary waveguides · CPC title

• G02B6/3566

  involving bending a beam, e.g. with cantilever · CPC title

• G02B6/3596

  With planar waveguide arrangement, i.e. in a substrate, regardless if actuating mechanism is outside the substrate · CPC title