Detecting Laser-Induced Fluorescence Emissions

• US 20080084562A1
• Filed: 09/30/2005
• Published: 04/10/2008
• Est. Priority Date: 10/01/2004
• Status: Active Grant

• Current Assignee: Centre National De La Recherche Scientifique
• Original Assignee: Centre National De La Recherche Scientifique
• Inventors: Bousquet, Bruno, Canioni, Lionel, Santran, Stephane
• Granted Patent: US 7,609,379 B2
• Time in Patent Office: Days
• US Class Current: 356/318
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/18 using diffraction elements, e.g. grating gratings per se G02B
• CPC Class Codes: G01J 3/4406 Fluorescence spectrometry
• CPC Class Codes: G01N 21/6402 Atomic fluorescence; Laser induced fluorescence

Abstract

A system for detecting a chemical element within a material including at least one laser emission means for ionizing part of the material to generate fluorescence; at least one transmitting Bragg grating that filters the wavelength corresponding to the deexcitation wavelength of the element; and at least one photodiode that detects a line corresponding to the filtering wavelength, wherein the at least one Bragg grating is mobile to vary the filtering wavelength.

Claims

1-9. -9. (canceled)

10. A system for detecting a chemical element within a material comprising:

at least one laser emission means for ionizing part of the material to generate fluorescence;

at least one transmitting Bragg grating that filters the wavelength corresponding to the deexcitation wavelength of the element; and

at least one photodiode that detects a line corresponding to the filtering wavelength, wherein the at least one Bragg grating is mobile to vary the filtering wavelength.

11. The system according to claim 10, wherein the photodiode is synchronizable with emissions from the laser.

12. The system according to claim 10, wherein the photodiode is activated with a delay with respect to the emission from the laser.

13. The system according to claim 11, wherein the photodiode is activated with a delay with respect to the emission from the laser.

14. The system according to claim 10, wherein the photodiode is an avalanche photodiode.

15. The system according to claim 10, further comprising a lens for focusing rays emitted by the Bragg grating towards the photodiode.

16. The system according to claim 10, further comprising a collimation mirror for collimating the fluorescence towards the Bragg grating.

17. The system according to claim 16, further comprising at least one optical fiber for transporting the fluorescence.

18. The system according to claim 17, wherein one end of the optical fiber corresponds to a focal point of the collimation mirror.

19. The system according to claim 16, wherein material is placed at a level of the focal point of the collimation mirror.