Methods and systems for imaging a sample using Raman spectroscopy

Patent metadata

Field	Value
Publication number	US-11105682-B2
Application number	US-201816647867-A
Country	US
Kind code	B2
Filing date	Sep 14, 2018
Priority date	Sep 14, 2017
Publication date	Aug 31, 2021
Grant date	Aug 31, 2021

Abstract

A system and method for imaging a sample using Raman spectrometry. Optical fibers having opposite first ends and second ends are arranged with the first ends and second ends in respective two-dimensional arrays. The two-dimensional arrays maintain relative positions of the optical fibers to one another from the first ends to the second ends in a way that the first end of each optical fibers of the bundle can simultaneously collect a corresponding Raman signal portion scattered from specific spatial coordinates of the area of the sample. The so-collected Raman signal portions are propagated towards the corresponding second end, from which are outputted and detected simultaneously using an array of detectors.

First claim

What is claimed is:

1. A method for imaging a sample using Raman spectroscopy, the method comprising:
illuminating an area of said sample with an excitation beam, spatial coordinates of said area emitting, in response to said illuminating, corresponding Raman signal portions each having corresponding spectral components;
collecting said Raman signal portions using first ends of a plurality of optical fibers extending between said first ends and second ends, said first ends and said second ends of said plurality of optical fibers being arranged in a respective one of two two-dimensional arrays, said two two-dimensional arrays maintaining relative positions of said plurality of optical fibers to one another from said first ends to said second ends in a manner that said collected Raman signal portions are propagated along the plurality of optical fibers while maintaining said relative positions from said first ends towards said second ends, from which said Raman signal portions are outputted;
receiving and directing at least some of said Raman signal portions signal outputted from said second ends of said plurality of optical fibers onto an array of detectors; and

said array of detectors generating image data indicative of an intensity of said Raman signal portions as function of said spatial coordinates of said area and as function of said spectral components of said Raman signal portions;
wherein said collecting said Raman signal portions is performed using an objective having a numerical aperture below 0.4 which is optically coupled to said first ends of said plurality of optical fibers, providing a field of view of said area of said sample exceeding 1 mm 2 .

2. The method of claim 1 wherein said two-dimensional array of said first ends of said plurality of optical fibers have a height and a width both exceeding 1 mm, providing a field of view of said area of said sample exceeding 1 mm 2 .

3. The method of claim 1 wherein said receiving and directing is performed using a tunable filter assembly optically coupled to said second ends of said plurality of optical fibers and leading to said array of detectors, said tunable filter assembly receiving said Raman signal portions and filtering out at least some spectral components therefrom, and repeating said receiving and said filtering out for remaining ones of said spectral components of said Raman signal portions.

4. The method of claim 1 wherein said receiving and imaging is performed using a scanning mirror assembly and an imaging spectrometer having an entry slit leading to said array of detectors, said scanning mirror assembly receiving and directing at least some of said Raman signal portions corresponding to a region of said spatial coordinates of said area of said sample, onto said entry slit, and repeating said receiving and said directing for remaining ones of said Raman signal portions, corresponding to remaining regions of said spatial coordinates of said area of said sample.

5. The method of claim 4 further comprising an objective assembly receiving said Raman signal portions from said second ends of said plurality of optical fibers and providing a focussed beam including said at least some of said Raman signal portions to said scanning mirror assembly, which directs at least some of said focussed beam of said Raman signal portions onto said entry slit.

6. A system for imaging a sample using Raman spectroscopy, the system comprising:
an excitation assembly configured to illuminate an area of said sample with an excitation beam, spatial coordinates of said area emitting, in response to said illumination, corresponding Raman signal portions each having corresponding spectral components;
a collection assembly comprising a plurality of optical fibers extending between first ends and second ends, said first ends and said second ends of said plurality of optical fibers being arranged in a respective one of two two-dimensional arrays, said first ends being positionable to collect said Raman signal portions from said area of said sample, said two two-dimensional arrays maintaining relative positions of said plurality of optical fibers to one another from said first ends to said second ends in a manner that said collected Raman signal portions are propagated along the plurality of optical fibers while maintaining said relative positions from said first ends towards said second ends, from which said Raman signal portions are outputted;
a scanning assembly configured to receive and image at least some of said Raman signal portions signal outputted from said second ends of said plurality of optical fibers onto a focal plane; and
an array of detectors at the focal plane positioned to receive said Raman signal portions from said scanning assembly and to generate image data indicative of an intensity of said Raman signal portions as function of said spatial coordinates of said area and as function of said spectral components of said Raman signal portions.

7. The system of claim 6 wherein said collection assembly comprises an objective having a numerical aperture below 0.4, the objective being optically coupled to said first ends of said plurality of optical fibers, providing a field of view of said area of said sample exceeding 1 mm 2 .

8. The system of claim 6 wherein said two-dimensional array of said first ends of said plurality of optical fibers have a height and a width both exceeding 1 mm, providing a field of view of said area of said sample exceeding 1 mm 2 .

9. A method for imaging a sample using Raman spectroscopy, the method comprising:
illuminating an area of said sample with an excitation beam, spatial coordinates of said area emitting, in response to said illuminating, corresponding Raman signal portions each having corresponding spectral components;
collecting said Raman signal portions using first ends of a plurality of optical fibers extending between said first ends and second ends, said first ends and said second ends of said plurality of optical fibers being arranged in a respective one of two two-dimensional arrays, said collected Raman signal portions propagating along said plurality of optical fibers from said first ends towards said second ends, from which said Raman signal portions are outputted;
receiving said outputted Raman signal portions and focussing said received Raman signal portions to form a focussed beam including at least some of said Raman signal portions;
receiving said focussed beam and directing a portion of said focussed beam towards an entry slit of an imaging spectrometer, said entry slit leading to an array of detector, said portion of said focussed beam including Raman signal portions corresponding to a region of said spatial coordinates of said area of said sample;
said array of detectors generating image data indicative of an intensity of said Raman signal portions as function of said spatial coordinates of said region and as function of said spectral components of said Raman signal portions; and
repeating said receiving said focussed beam, said directing and said generating for remaining portions of said focussed beam, by moving said focussed beam relative to said entry slit, said remaining portions corresponding to remaining regions of said spatial coordinates of said area of said sample.

10. The method of claim 9 wherein said receiving said Raman signal portions is performed using an objective having a numerical aperture below 0.4 which is optically coupled to said first ends of said plurality of optical fibers, providing a field of view of said area of said sample exceeding 1 mm 2 .

11. The method of claim 9 wherein said two-dimensional array of said first ends of said plurality of op

Assignees

• Polyvalor Lp

Inventors

• Leblond Frederic
• St-Arnaud Karl
• Daoust Francois

Classifications

• G01J3/06

  Scanning arrangements {arrangements for order-selection} · CPC title

• G01J3/0218

  using optical fibers · CPC title

• G01N21/65 Primary

  Raman scattering · CPC title

• G01J3/024

  using means for illuminating a slit efficiently (e.g. entrance slit of a spectrometer or entrance face of fiber) · CPC title

• G01J3/021

  using plane or convex mirrors, parallel phase plates, or particular reflectors · CPC title