Apparatus with cantilever light guide

Patent metadata

Field	Value
Publication number	US-11828592-B2
Application number	US-202016841152-A
Country	US
Kind code	B2
Filing date	Apr 6, 2020
Priority date	Apr 8, 2019
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

An apparatus comprising: a void; an interferometer detector; andlight guide means for guiding a light signal along a light path to the interferometer detector wherein the light path comprises a cantilever light guide that is supported such that a free-end can move within the void and the interferometer detector is configured to detect a deflection of the free-end of the cantilever light guide; anda reflector, wherein the cantilever light guide comprises a light outcoupler configured to out-couple the light signal to extend the light path from the cantilever light guide to the reflector.

First claim

I claim:

1. An apparatus comprising:
a void;
a reflector;
an interferometer detector configured to receive a first portion of a light signal at a first phase wherein the first portion of the light signal travels a first interferometric light path from a light source through an optical loop in a reference arm; and
a cantilever light guide supported at a first end and unsupported at a second opposing end, the cantilever light guide consisting of a light guide, the light guide being a self-supporting member configured to guide a second portion of the light signal at a second phase, wherein the cantilever light guide is supported such that the second opposing end is a free-end of the cantilever light guide and can move within the void,
wherein the second portion of the light signal travels a second interferometric light path from the light source through the cantilever light guide;
wherein the cantilever light guide comprises a light outcoupler configured to out-couple the second portion of the light signal to extend the light path from the cantilever light guide to the reflector and wherein the interferometer detector is configured to detect a deflection of the free-end of the cantilever light guide based at least in part on the out-coupled second portion of the light signal after reflection by the reflector; and
wherein the deflection of the free-end of the cantilever light guide increases a difference between the first phase of the first portion of the light signal and the second phase of the second portion of the light signal to improve a sensitivity of the apparatus.

2. An apparatus as claimed in claim 1 , wherein the light outcoupler comprises periodic diffraction elements.

3. An apparatus as claimed in claim 1 , wherein the reflector is a plane reflector that is substantially parallel to the cantilever light guide when the cantilever light guide is at rest.

4. An apparatus as claimed in claim 1 , wherein the cantilever light guide in an integral component of a first substrate and the reflector is an integral component of a second substrate adjacent the first substrate.

5. An apparatus as claimed in claim 1 ,
wherein the interferometer detector detects a change in a length of the first interferometric light path compared to the second branch of tho interferometric light path.

6. An apparatus as claimed in claim 1 , wherein the interferometer detector is calibrated to measure a deflection of the cantilever light guide.

7. An apparatus as claimed in claim 1 , wherein the interferometer detector comprises one or more phase shifters for calibrating the interferometer detector.

8. An apparatus as claimed in claim 1 , wherein the second interferometric light path has an outward portion and a return portion.

9. An apparatus as claimed in claim 1 , wherein the cantilever light guide and the interferometer detector are formed from a single monolithic substrate.

10. An apparatus as claimed in claim 9 , further comprising an additional monolithic substrate defining the reflector.

11. An apparatus as claimed in claim 10 , wherein the additional monolithic substrate comprises an excitation radiation source for generating a photoacoustic signal from a sample in the void.

12. A sensing system comprising:
a void;
a reflector;
an interferometer detector configured to receive a first portion of a light signal at a first phase wherein the first portion of the light signal travels a first interferometric light path from a light source through an optical loop in a reference arm; and
a cantilever light guide supported at a first end and unsupported at a second opposing end, the cantilever light guide consisting of a light guide, the light guide being a self-supporting member configured to guide a second portion of the light signal at a second phase, wherein the cantilever light guide is supported such that the second opposing end is a free-end of the cantilever light guide and can move within the void, wherein the second portion of the light signal travels a second interferometric light path from the light source through the cantilever light guide;
wherein the cantilever light guide comprises a light outcoupler configured to out-couple the second portion of the light signal to extend the light path from the cantilever light guide to the reflector and wherein the interferometer detector is configured to detect a deflection of the free-end of the cantilever light guide based at least in part on the out-coupled second portion of the light signal after reflection by the reflector;
wherein the deflection of the free-end of the cantilever light guide increases a difference between the first phase of the first portion of the light signal and the second phase of the second portion of the light signal to improve a sensitivity of the sensing system; and
wherein the sensing system is configured for atomic force microscopy, microscale chemical sensing, accelerometry or acoustic sensing.

13. An apparatus as claimed in claim 12 , wherein the light outcoupler comprises periodic diffraction elements.

14. An apparatus as claimed in claim 12 , wherein the reflector is a plane reflector that is substantially parallel to the cantilever light guide when the cantilever light guide is at rest.

15. An apparatus as claimed in claim 12 , wherein the cantilever light guide in an integral component of a first substrate and the reflector is an integral component of a second substrate adjacent the first substrate.

16. An apparatus as claimed in claim 12 , wherein the interferometer detector is calibrated to measure a deflection of the cantilever light guide.

Assignees

• Nokia Technologies Oy

Inventors

• Bitauld David

Classifications

• G01B9/02051 Primary

  Integrated design, e.g. on-chip or monolithic · CPC title

• G01B9/02027

  Two or more interferometric channels or interferometers · CPC title

• G02B6/4214

  the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device (G02B6/4246 takes precedence) · CPC title

• G02B6/4246

  Bidirectionally operating package structures · CPC title

• G01B11/161

  by interferometric means · CPC title