Light guiding measuring cell for use in flow cytometry

Patent metadata

Field	Value
Publication number	US-10281389-B2
Application number	US-201515509682-A
Country	US
Kind code	B2
Filing date	Sep 8, 2015
Priority date	Sep 9, 2014
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

A measuring cell includes a cavity for receiving a test sample to be used in a particle detection apparatus. The measuring cell is configured as an optical waveguide for guiding a light beam. The waveguide has a core which has a refractive index nK, extends along a longitudinal axis of the waveguide, has a cross-sectional area AK of less than 80 μm2 in a cross section perpendicular to the longitudinal axis, and which is surrounded by a cladding having a smaller refractive index than nK. The cavity forms a channel. The channel extends along the longitudinal axis, is formed inside of or in contact with the core, and has at least one open end with an opening area AH of less than 0.2 μm2.

First claim

The invention claimed is:

1. Measuring cell configured for use in flow cytometry, the measuring cell having a cavity for receiving a test sample, the measuring cell being configured as an optical waveguide for guiding a light beam, said waveguide ( 1 ) comprising a core ( 3 ) having a refractive index n k , the core ( 3 ) extending along a longitudinal axis ( 9 ) of said waveguide ( 1 ), the core ( 3 ) having a cross-sectional area A K of less than 80 μm 2 in a cross section perpendicular to the longitudinal axis ( 9 ), and the core ( 3 ) being surrounded by a cladding ( 2 ) having a smaller refractive index than n K ,
wherein said cavity forms a channel ( 4 ) extending along the longitudinal axis ( 9 ), the channel ( 4 ) being formed inside of or in contact with said core ( 3 ), and the channel ( 4 ) having at least one open end with an opening area A H of less than 0.2 μm 2 , and
wherein the core ( 3 ) and the cladding ( 2 ) are made of massive, solid material.

2. Measuring cell according to claim 1 , wherein the difference between the refractive indices of the core ( 3 ) and the cladding ( 2 ), the cross-sectional area of the core ( 3 ) and the wavelength of the guided light beam are coordinated such that the fundamental mode of the light beam and not more than 20 further modes may be propagated.

3. Measuring cell according to claim 1 , wherein the core ( 3 ) and the cladding ( 2 ) are composed of highly siliceous glass.

4. Measuring cell according to claim 3 , wherein the core ( 3 ) consists of quartz glass doped with germanium oxide, and wherein the cladding ( 2 ) consists of quartz glass which is not doped or which is doped with a component capable of decreasing the refractive index of quartz glass.

5. Measuring cell according to claim 3 , wherein the core ( 3 ) consists of undoped quartz glass, and wherein the cladding ( 2 ) consists of quartz glass having a refractive index n c , said quartz glass being doped with a component capable of decreasing the refractive index of quartz glass.

6. Measuring cell according to claim 5 , wherein the difference of n k −n c is at least 16×10 −3 .

7. Measuring cell according to claim 1 , wherein in a cross-section perpendicular to the longitudinal axis, the channel ( 4 ) is circular and has a diameter in the range of 20 nm to 500 nm.

8. Measuring cell according to claim 1 , wherein in a cross-section perpendicular to the longitudinal axis, the core ( 3 ) is circular and has a diameter of less than 10 μm, and a core center point which is located inside a respective cross-sectional area of the channel ( 4 ).

9. Measuring cell according to claim 7 , wherein the channel ( 4 ) extends entirely inside the core ( 3 ), and wherein the ratio A K /A H is greater than 4.

10. Measuring cell according to claim 1 , wherein the core ( 3 ), the cladding ( 2 ) and the channel ( 4 ) extend coaxially to each other.

11. Measuring cell according to claim 1 , wherein the optical waveguide is configured as a step-index fiber ( 1 ) having the channel ( 4 ), the channel ( 4 ) having an opening width which is smaller than the wavelength of the light beam to be guided.

12. Measuring cell according to claim 1 , wherein the optical waveguide is configured as an optical fiber ( 1 ) with a circular cross-section, and wherein the cladding ( 2 ) has an outer diameter in the range of 150 μm to 300 μm.

13. Measuring cell according to claim 5 , wherein the difference of n k −n c is at least 20×10 −3 .

14. Measuring cell according to claim 1 , wherein in a cross-section perpendicular to the longitudinal axis, the channel ( 4 ) is circular and has a diameter in the range of 50 to 300 nm.

15. Measuring cell according to claim 1 , wherein in a cross-section perpendicular to the longitudinal axis, the core ( 3 ) is circular and has a diameter of less than 3 μm, and a core center point which is located inside a respective cross-sectional area of the channel ( 4 ).

16. Measuring cell according to claim 7 , wherein the channel ( 4 ) extends entirely inside the core ( 3 ), and wherein the ratio A K /A H is greater than 20.

Assignees

• Heraeus Quarzglas

Inventors

• Weidlich Stefan
• Schmitt Clemens
• Werner Jörg
• Schmidt Markus
• Kobelke Jens

Classifications

• G01N2201/08

  Optical fibres; light guides · CPC title

• G01N21/05 Primary

  Flow-through cuvettes (G01N21/09 takes precedence; handling fluid samples G01N1/10) · CPC title

• G01N21/33

  using ultraviolet light (G01N21/39 takes precedence) · CPC title

• G01N21/35

  using infrared light (G01N21/39 takes precedence) · CPC title

• G01N2021/0378

  Shapes · CPC title