MODULAR PHOTOACOUSTIC DETECTION DEVICE

• US 20160356700A1
• Filed: 06/06/2016
• Published: 12/08/2016
• Est. Priority Date: 06/08/2015
• Status: Active Application

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: ROUXEL, Justin, Brun, Mickael, Gliere, Alain, Nicoletti, Sergio
• Granted Patent: US 10,288,553 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 2021/1704 in gases
• CPC Class Codes: G01N 2021/1708 with piezotransducers probes for investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves G01N29/24
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids
• CPC Class Codes: G01N 2201/0245 with insertable-removable part
• CPC Class Codes: G01N 2291/021 Gases
• CPC Class Codes: G01N 2291/02872 Pressure
• CPC Class Codes: G01N 29/2418 using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046
• CPC Class Codes: G01N 29/2425 optoacoustic fluid cells therefor

Abstract

Modular photoacoustic detection device comprising:

• • a photoacoustic cell including at least two chambers connected by at least two capillaries and forming a Helmholtz type differential acoustic resonator;
  • acoustic detectors coupled to the chambers;
  • a light source capable of emitting a light beam having at least one wavelength capable of exciting a gas intended to be detected and which can be modulated to a resonance frequency of the photoacoustic cell;
  • a first photonic circuit optically coupling the light source to an input face of a first of the chambers;

wherein the first photonic circuit is arranged in a detachable manner in a first housing formed in the acoustic cell and emerging on the input face of the first chamber.

Claims

1. Modular photoacoustic detection device comprising at least:

a photoacoustic cell including at least two chambers connected by at least two capillaries and forming a Helmholtz type differential acoustic resonator;

acoustic detectors coupled to the chambers;

a light source capable of emitting a light beam having at least one wavelength capable of exciting a gas intended to be detected and which can be modulated to a resonance frequency of the photoacoustic cell;

a first photonic circuit optically coupling the light source to an input face of a first of the chambers;

wherein the first photonic circuit is arranged in a detachable manner in a first housing formed in the acoustic cell and emerging on the input face of the first chamber.

2. Device according to claim 1, wherein the acoustic detectors are coupled in a detachable manner to the photoacoustic cell.

3. Device according to claim 1, wherein the photoacoustic cell comprises at least one stack of a first and of a second layer of material in which are formed the chambers, the capillaries, the first housing, at least two openings each emerging in one of the capillaries and at least two locations each communicating with one of the chambers and in which the acoustic detectors are arranged.

4. Device according to claim 3, wherein:

the locations are formed in a part of the thickness of the first layer and cross through an upper face of the first layer;

the openings cross through the entire thickness of the first layer;

a first part of each of the chambers is formed in a part of the thickness of the first layer and crosses through a lower face of the first layer opposite to the upper face of the first layer;

the capillaries are formed in a part of the thickness of the first layer and cross through the lower face of the first layer;

a second part of each of the chambers is formed in a part of the thickness of the second layer and crosses through an upper face of the second layer which is arranged against the lower face of the first layer, the first and second parts of each of the chambers being arranged facing each other;

the first housing is formed in a part of the thickness of the second layer and crosses through the upper face of the second layer.

5. Device according to claim 1, wherein the photoacoustic cell comprises at least one stack of a first, second, third and fourth layers of material in which are formed the chambers, the capillaries, the first housing, at least two openings each emerging in one of the capillaries and at least two locations each communicating with one of the chambers and in which the acoustic detectors are arranged.

6. Device according to claim 5, wherein:

the capillaries cross through the entire thickness of the second layer, the first and third layers between which is located the second layer forming upper and lower walls of the two capillaries;

the chambers and the first housing cross through the entire thickness of the third layer, the second and fourth layers between which is located the third layer forming upper and lower walls of the chambers and of the first housing;

the locations cross through the entire thickness of the fourth layer;

the openings cross through the entire thickness of the third and fourth layers.

7. Device according to claim 1, wherein the photoacoustic cell is formed of a monolithic part of sintered powders.

8. Device according to claim 1 wherein the light source is optically coupled to an input face of the first photonic circuit by at least one collimation system comprising at least one lens, and wherein the first photonic circuit forms at least one waveguide.

9. Device according to claim 1, wherein the light source is capable of emitting a light beam having several wavelengths and is arranged against the first photonic circuit which forms an arrayed waveguide grating multiplexer—

demultiplexer circuit.

10. Device according to claim 1, wherein the light source is optically coupled to an input face of the first photonic circuit by at least one optic fiber, and wherein the first photonic circuit forms at least one waveguide or an arrayed waveguide grating multiplexer—

demultiplexer circuit.

11. Device according to claim 1, further comprising at least one first cooling system capable of thermally adjusting the light source and, when the light source is not arranged against the first photonic circuit, a second cooling system capable of thermally adjusting the photoacoustic cell independently of the light source.

12. Device according to claim 1, wherein the photoacoustic cell further comprises at least one second housing emerging on an output face of the first chamber, and further comprising at least one second photonic circuit optically coupling the output face of the first chamber to an optical detector and arranged in a detachable manner in the second housing.

13. Device according to claim 1, wherein the photoacoustic cell comprises one or more metals.

14. Device according to claim 1, wherein the distance between the two capillaries is equal to around half of the length of at least one of the chambers.

15. Gas detection device, comprising at least one device according to claim 1 and gas input and output channels communicating with the chambers of the photoacoustic detection device, and wherein said at least one wavelength of the light beam capable of being emitted by the light source corresponds to at least one absorption wavelength of at least one gas intended to be detected.

16. Method for producing a modular photoacoustic detection device, comprising at least the steps of:

producing at least one photoacoustic cell including at least two chambers connected by at least two capillaries and forming a Helmholtz type differential acoustic resonator;

coupling of acoustic detectors to the chambers;

producing at least one light source capable of emitting a light beam having at least one wavelength capable of making the photoacoustic cell resonate;

producing at least one first photonic circuit arranged in a detachable manner in a first housing formed in the acoustic cell and emerging on an input face of a first of the chambers, and optically coupling the light source to the input face of the first chamber.

17. Method according to claim 16, wherein:

the production of the photoacoustic cell comprises the production of at least one stack of a first and of a second layer of material in which are formed, by chemical etching implemented in a part of the thickness of each of the first and second layers, the chambers, the capillaries, the first housing, at least two openings each emerging in one of the capillaries and at least two locations each communicating with one of the chambers and in which the acoustic detectors are arranged, or

the production of the photoacoustic cell comprises the production of at least one stack of a first, second, third and fourth layers of material in which are formed, by chemical etching or laser implemented in the entire thickness of each of the second, third and fourth layers, the chambers, the capillaries, the first housing, at least two openings each emerging in one of the capillaries and at least two locations each communicating with one of the chambers and in which the acoustic detectors are arranged, or

the photoacoustic cell is formed of a monolithic part of sintered metal powders obtained by 3D printing.