# US 7,609,379 B2 · Detecting laser-induced fluorescence emissions

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- Number: US 7,609,379 B2
- Document ID: US7609379B2
- Status: Granted
- Kind: B2
- Application number: 11/664,432
- Filed: 2005-09-30
- Published: 2008-04-10
- Granted: 2009-10-27
- Earliest claimed: 2004-10-01
- Assignees: Centre National de la Recherche Scientifique (CNRS)
- Inventors: Lionel Canioni; Stéphane Santran; Bruno Bousquet
- Web page: https://patentgrep.com/patent/US7609379B2

## CPC

- G01J 3/02: Details
- G01J 3/0218: {using optical fibers}
- G01J 3/18: using diffraction elements, e.g. grating (gratings per se G02B)
- G01J 3/4406: {Fluorescence spectrometry}
- G01N 21/6402: {Atomic fluorescence; Laser induced fluorescence}
- G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## 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

### Claim 1

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.

### Claim 2 (depends on 1)

The system according to claim 1, wherein the photodiode is synchronizable with emissions from the laser.

### Claim 3 (depends on 1)

The system according to claim 1, wherein the photodiode is activated with a delay with respect to the emission from the laser.

### Claim 4 (depends on 2)

The system according to claim 2, wherein the photodiode is activated with a delay with respect to the emission from the laser.

### Claim 5 (depends on 1)

The system according to claim 1, wherein the photodiode is an avalanche photodiode.

### Claim 6 (depends on 1)

The system according to claim 1, further comprising a lens for focusing rays emitted by the Bragg grating towards the photodiode.

### Claim 7 (depends on 1)

The system according to claim 1, further comprising a collimation mirror for collimating the fluorescence towards the Bragg grating.

### Claim 8 (depends on 7)

The system according to claim 7, further comprising at least one optical fiber for transporting the fluorescence.

### Claim 9 (depends on 8)

The system according to claim 8, wherein one end of the optical fiber corresponds to a focal point of the collimation mirror.

### Claim 10 (depends on 7)

The system according to claim 7, wherein material is placed at a level of the focal point of the collimation mirror.