Optical detector of particles

Patent metadata

Field	Value
Publication number	US-11204308-B2
Application number	US-201816480136-A
Country	US
Kind code	B2
Filing date	Jan 25, 2018
Priority date	Jan 25, 2017
Publication date	Dec 21, 2021
Grant date	Dec 21, 2021

Abstract

The present invention relates to a particle detector comprising at least an optical device configured to emit a luminous radiation; and a substrate extending in a plane and defining a channel intended to receive particles, the channel extending principally in a direction perpendicular to the principal plane; characterised in that the detector comprises a matrix of photo detectors and a reflecting surface; the matrix of photo detectors and the reflecting surface being disposed on mutually parallel planes and situated on either side of said portion of the substrate so that a part of the luminous radiation passes through the channel by being diffracted by a particle, then reflects off the reflecting surface, and then reaches the matrix of photo detectors.

First claim

The invention claimed is:

1. A particle detector comprising:
an optical device able to be connected to at least one light source and configured to emit at least one luminous radiation generated by said light source; and
a substrate extending in a principal plane and defining a portion at least of at least one channel intended to receive a fluid comprising particles, said at least one channel extending principally in a direction perpendicular to the principal plane, a portion at least of the substrate being configured to receive a portion at least of the luminous radiation emitted by the optical device;
wherein the detector further comprises a matrix of photo detectors and at least one reflecting surface;
the matrix of photo detectors being arranged in a first plane and the reflecting surface being oriented in a second plane, said first and second planes being parallel to the principal plane and situated on either side of said portion of the substrate, so that a portion at least of the luminous radiation emitted by the optical device passes through said at least one channel by being diffracted by at least one particle, then reflects off the reflecting surface, and then reaches the matrix of photo detectors.

2. The detector according to claim 1 wherein the optical device is situated at least partially between said first and second planes.

3. The detector according to claim 1 wherein the substrate has a first face turned facing or arranged in contact with the reflecting surface and wherein the substrate has a second face, opposite the first face and turned facing or arranged in contact with the matrix of photo detectors.

4. The detector according to claim 1 wherein the matrix of photo detectors and the reflecting surface are situated at least partially and in line with one another along said perpendicular direction.

5. The detector according to claim 1 configured so that a portion at least of the luminous radiation is reflected by a portion at least of the reflecting surface before passing through said at least one channel to be diffracted by at least one particle.

6. The detector according to claim 1 wherein the substrate is formed from at least one material allowing at least 50% of said luminous radiation to pass.

7. The detector according to claim 1 wherein the optical device has a distal portion through which the luminous radiation is emitted and wherein the distal portion and the matrix of photo detectors are situated on either side of said at least one channel with respect to said perpendicular direction.

8. The detector according to claim 1 wherein the optical device and the matrix of photo detectors are arranged in the substrate.

9. The detector according to claim 1 wherein the optical device and the matrix of photo detectors are arranged outside of the at least one channel in such a way as to be protected from a direct contact with the fluid comprising particles.

10. The detector according to claim 1 wherein the matrix of photo detectors extends around said at least one channel by covering an arc of circle of at least 180°.

11. The detector according to claim 1 wherein the substrate comprises at least a first substrate and a second substrate, the first substrate bearing the matrix of photo detectors and a portion of the optical device and the second substrate bearing at least the reflecting surface.

12. The detector according to claim 1 wherein the substrate comprises at least a first substrate and a second substrate, the first substrate bearing at least a first portion of said at least one channel and the second substrate bearing at least a second portion of said at least one channel, each portion extending in said perpendicular direction and wherein an average surface area of a cross-section of the first portion is substantially less than or equal to an average surface area of a cross-section of the second portion, an average surface area of the cross-section of a portion corresponding to a mean of surface areas of cross-sections taken over an entire height along the perpendicular direction.

13. The detector according to claim 1 wherein the optical device comprises at least one distal portion shaped to form, at an outlet of the optical device, an extraction network configured to generate a set of extracted light rays and wherein the extraction network has a shape that flares in the principal plane in the direction of said at least one channel.

14. The detector according to claim 1 wherein the optical device comprises at least one waveguide comprising a core that has a distal portion and a sheath covering the core, the core having, on the distal portion, a plurality of grooves arranged periodically according to a pitch P such that P satisfies the following expression:

λ

n
eff

≤
P
≤

λ

n
eff

-

n
g

with: λ being a wavelength of the luminous radiation;
n eff being an effective index of refraction of a fundamental mode of the luminous radiation;
n e being an index of refraction of the core of the waveguide;
n g being an index of refraction of the sheath of the waveguide; and
n eff being between n e and n g .

15. The detector according to claim 1 wherein the optical device comprises at least one waveguide comprising a core and a sheath and wherein a thickness h of the waveguide measured along said perpendicular direction is such that:

h
≤

2
⁢
λ

π
⁢

n
c
2

-

n
g
2

with: λ being a wavelength of the luminous radiation;
n e being an index of refraction of the core of the waveguide; and
n g being an index of refraction of the sheath of the waveguide.

16. The detector according to claim 1 comprising at least a first channel and a second channel for circulation of particles, each channel being intended to receive the fluid comprising particles and being configured to receive a portion at least of the luminous radiation emitted by the optical device.

17. The detector according to claim 16 , configured in such a way that the luminous radiation received by each channel comes from a single light source.

18. The detector according to claim 1 comprising at least a first and at least a second channel for circulation of particles and wherein the optical device comprises at least one waveguide comprising at least one junction configured to form at least a first arm of the waveguide and at least

Assignees

• Commissariat Energie Atomique

Inventors

• Boutami Salim
• Nicoletti Sergio

Classifications

• G01N15/0211 Primary

  Investigating a scatter or diffraction pattern · CPC title

• G01N2015/0046

  in gas, e.g. smoke · CPC title

• G01N15/1436

  the optical arrangement forming an integrated apparatus with the sample container, e.g. a flow cell · CPC title

• G01N21/53

  within a flowing fluid, e.g. smoke · CPC title

• G01N15/14

  Optical investigation techniques, e.g. flow cytometry · CPC title