Infrared radiation source

• US 10,641,702 B2
• Filed: 10/10/2018
• Issued: 05/05/2020
• Est. Priority Date: 10/12/2017
• Status: Expired due to Fees

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Boutami, Salim, Gliere, Alain
• Primary Examiner(s): Vanore, David A
• Application Number:
  US16/156,139
• Publication Number:
  US 20190113446A1
• Time in Patent Office: 573 Days
• Field of Search: 2503381, 250504 R, 2502081, 257432, 257467, 359245
• CPC Class Codes: G01J 2003/1226 Interference filters
• CPC Class Codes: G01J 3/108 for measurement in the infrared range
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 2201/06186 Resistance heated; wire sources; lamelle sources

Abstract

A source (100) that includes a membrane, where the membrane includes: an emissive layer (130) including an emissive surface (131); an adaptor (121a, 121b, 121c, 121d), each adaptor (121a, 121b, 121c, 121d) facing a different section of the emissive section (131), called the emissive section (132a, 132b, 132c, 132d), and with which it forms an emissive assembly (134a, 134b, 134c, 134d) adapted to reduce the spectral extent of infrared radiation emitted by the emissive section; and a plurality of heaters (140a, 140b) for heating the emissive layer (130), the heaters (140a, 140b) being arranged so as to impose different relative temperature variations in different emissive sections (132a, 132b, 132c, 132d).

Claims

1. An infrared radiation source (100) comprising a membrane, the membrane comprising:

an emissive layer (130), comprising an emissive surface (131), which emits infrared radiation from said emissive surface (131) when it is heated;

a plurality of adaptation means (121a, 121b, 121c, 121d), each adaptation means (121a, 121b, 121c, 121d) facing a different section of the emissive surface (131) called the emissive section (132a, 132b, 132c, 132d), and with which it forms an emissive assembly (134a, 134b, 134c, 134d) that emits infrared radiation with a smaller spectral range than the infrared radiation that can be emitted by the emissive section (132a, 132b, 132c, 132d) alone, and centered around a central wavelength, said central wavelength being different from one emissive assembly to the other,

a plurality of means (140a, 140b) of heating the emissive layer (130), the heating means (140a, 140b) being arranged so as to impose a variable temperature gradient on the emissive layer so as to vary the relative distributions of infrared radiation wavelengths effectively emitted by each of the emissive assemblies (134a, 134b, 134c, 134d).

2. The source according to claim 1, wherein each adaptation means (121a, 121b, 121c, 121d) comprises a filter.

3. The source according to claim 1, wherein the adaptation means (121a, 121b, 121c, 121d) are in line.

4. The source according to claim 1, wherein the emissive layer (130) comprises one or more through trenches (133) separating the emissive sections (132a, 132b, 132c, 132d) from each other.

5. The source according to claim 1, wherein the infrared radiation source is located in a chamber in which the environment is kept at a pressure of less than 10⁻

2 mbars.

6. A gas detector comprising:

the infrared radiation source according to claim 1; and

an optical sensor.

7. The source according to claim 1, wherein each adaptation means (121a, 121b, 121c, 121d) comprises an interference filter.

8. The source according to claim 1, wherein the emissive layer (130) is supported on a mechanical support (160) on a face opposite the emissive surface (131).

9. The source according to claim 8, wherein the plurality of heating means (140a, 140b) comprises at least two metallic tracks that are heated when a current passes through them.

10. The source according to claim 9, wherein the two metallic tracks are parallel to each other, and surround the emissive surface (131).

11. The source according to claim 8, wherein the two tracks are formed on the mechanical support (160) and at a distance from the emissive layer (130).

12. The source according to claim 8, wherein the mechanical support (160) is provided with at least two attachment legs (161a, 161b, 161c, 161d).

13. The source according to claim 12, wherein the plurality of heating means (140a, 140b) comprises at least two metallic tracks that are heated when a current passes through them, and in which the attachment legs are also provided with current inputs (162a, 162b, 162c, 162d) to supply power to the metallic tracks.

14. The source according to claim 8, wherein a dielectric layer (150) with a refraction index n and a thickness E is intercalated between the plurality of adaptation means (121a, 121b, 121c, 121d) and the emissive layer 130.

15. The source according to claim 14, each adaptation means (121a, 121b, 121c, 121d) comprises at least one metallic pad supported on the dielectric layer (150), with a dimension w that is an integer multiple of the central wavelength associated with the emissive assembly (134a, 134b, 134c, 134d) considered divided by twice the refraction index of the dielectric layer at said central wavelength.

16. The source according to claim 15, wherein h each adaptation means (121a, 121b, 121c, 121d) is at a spacing from the emissive surface (131) equal to a distance less than one tenth of the central wavelength associated with the emissive assembly (134a, 134b, 134c, 134d) considered.

17. The source according to claim 16, wherein each adaptation means (121a, 121b, 121c, 121d) comprises the same number of metallic pads (122a, 122b, 122c, 122d).

18. The source according to claim 15, wherein the at least one metallic pad comprises a plurality of metal pads (122a, 122b, 122c, 122d) arranged in a matrix layout, for each adaptation means (121a, 121b, 121c, 121d).

19. The source according to claim 15, wherein the at least one metallic pad comprises a metallic species selected from the group consisting of platinum, gold, silver, titanium, titanium nitride, tungsten, palladium, tantalum, copper, aluminium, palladium, and molybdenum.

20. The source according to claim 15, wherein h each adaptation means (121a, 121b, 121c, 121d) is at a spacing from the emissive surface (131) equal to a distance more than one fifteenth and less than one tenth of the central wavelength associated with the emissive assembly (134a, 134b, 134c, 134d) considered.

21. The source according to claim 8, wherein the mechanical support (160) is provided with at least four attachment legs (161a, 161b, 161c, 161d).

22. The source according to claim 1, wherein the infrared radiation source is located in a chamber in which the environment is kept at a pressure between 10⁻

3 mbars and 10<sup>−

2</sup> mbars.