Systems and methods for a time-based optical pickoff for mems sensors

Patent metadata

Field	Value
Publication number	US-2016377434-A1
Application number	US-201514860443-A
Country	US
Kind code	A1
Filing date	Sep 21, 2015
Priority date	Jun 26, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

Systems and methods for a time-based optical pickoff for MEMS sensors are provided. In one embodiment, a method for an integrated waveguide time-based optical-pickoff sensor comprises: launching a light beam generated by a light source into an integrated waveguide optical-pickoff monolithically fabricated within a first substrate, the integrated waveguide optical-pickoff including an optical input port, a coupling port, and an optical output port; and detecting changes in an area of overlap between the coupling port and a moving sensor component separated from the coupling port by a gap by measuring an attenuation of the light beam at the optical output port, wherein the moving sensor component is moving in-plane with respect a surface of the first substrate comprising the coupling port and the coupling port is positioned to detect movement of an edge of the moving sensor component.

First claim

We claim:

1 . A method for an integrated waveguide time-based optical-pickoff sensor, the method comprising:
launching a light beam generated by a light source into an integrated waveguide optical-pickoff monolithically fabricated within a first substrate, the integrated waveguide optical-pickoff including an optical input port, a coupling port, and an optical output port; and detecting changes in an area of overlap between the coupling port and a moving sensor component separated from the coupling port by a gap by measuring an attenuation of the light beam at the optical output port, wherein the moving sensor component is moving in-plane with respect a surface of the first substrate comprising the coupling port and the coupling port is positioned to detect movement of an edge of the moving sensor component.

2 . The method of claim 1 , further comprising:
driving the moving sensor component into in-plane vibration such that an edge of the moving sensor component moves back and forth in an oscillating manner covering and uncovering the coupling port.

3 . The method of claim 1 , further comprising:
measuring a timing of an oscillating optical output from the optical output port.

4 . The method of claim 3 , further comprising:
measuring an in-plane displacement of the moving sensor component based on the oscillating optical output.

5 . The method of claim 1 , further comprising:
determining an amount of overlap between the sensor component and the coupling port based on the attenuation of the light beam at the optical output port.

6 . The method of claim 1 , wherein the moving sensor component is a micro-electromechanical system (MEMS) inertial sensor proof mass.

7 . The method of claim 1 , wherein the light source is fabricated within an interposer layer adjacent to the first substrate.

8 . The method of claim 1 , wherein the light source is a light-emitting diode (LED).

9 . The method of claim 1 , wherein the light source is a laser light source.

10 . An integrated optical read out sensor, the sensor comprising:
at least a first glass substrate; an integrated waveguide optical-pickoff monolithically fabricated within the first glass substrate and comprising an optical input port, a coupling port, and an optical output port; a moving sensor component adjacent to the coupling port and having a degree-of-freedom of in-plane motion with respect to the coupling port of the integrated waveguide, wherein the coupling port is positioned relative to an edge of the moving sensor component such that an area of overlap between the coupling port and the moving sensor component changes with in-plane motion of the moving sensor component; a light source that launches light into the first glass substrate via the optical input port, wherein a portion of the light couples from the coupling port to the moving sensor component as a function of the area of overlap between the coupling port and the moving sensor component; at least one photodetector coupled to the optical output port; and electronics coupled to the at least one photodetector that calculates a measurement based on an attenuation of optical intensity of the light exiting from the optical output port, wherein the attenuation is at least in part a function of the area of overlap.

11 . The sensor of claim 10 , wherein the electronics measures a timing of an oscillating optical output from the optical output port to detecting an amount of coupling of the light from the coupling port to the moving sensor component.

12 . The sensor of claim 11 , wherein the electronics calculates an in-plane displacement of the moving sensor component based on the oscillating optical output.

13 . The sensor of claim 10 , wherein the electronics calculates an amount of overlap between the sensor component and the coupling port based on the attenuation of the light beam at the optical output port.

14 . The sensor of claim 10 , wherein the moving sensor component is a micro-electromechanical system (MEMS) inertial sensor proof mass.

15 . The sensor of claim 10 , wherein the moving sensor component is a micro-electromechanical system (MEMS) gyroscope inertial sensor proof mass.

16 . The sensor of claim 10 , wherein the moving sensor component is a micro-electromechanical system (MEMS) accelerometer inertial sensor proof mass.

17 . The sensor of claim 10 , wherein the light source is fabricated within an interposer layer adjacent to the first substrate

18 . The sensor of claim 10 , wherein the light source is a light-emitting diode (LED).

19 . The sensor of claim 10 , wherein the light source is a laser light source.

Assignees

• Honeywell Int Inc

Inventors

• Horning Robert D
• Lodden Grant

Classifications

• G01P15/032

  by measuring the displacement of a movable inertial mass · CPC title

• G01C19/574

  the devices having two sensing masses in anti-phase motion · CPC title

• G01C19/5726 Primary

  Signal processing · CPC title

• G02B6/29331

  operating by evanescent wave coupling · CPC title

• G01C19/5621

  the devices involving a micromechanical structure · CPC title