Hollow core waveguide flow cell
View Patent ↗A flow cell for use with a spectrometer is described. The flow cell includes a waveguide having a hollow core. An inlet is fluidly coupled at a first end of the hollow core, and an outlet is fluidly coupled at a second end of the hollow core. A window at the inlet is optically coupled to the waveguide at the second end, and a mirror at the outlet is optically coupled to the waveguide at the second end. The flow cell also includes a first conduit configured to couple a fluid to the inlet, and a second conduit configured to couple the fluid to the outlet. Methods and systems using the flow cell are described. For example, methods and systems for monitoring a bioreactor.
1 . A flow cell comprising:
a waveguide having a hollow core;
an inlet fluidly coupled at a first end of the hollow core;
an outlet fluidly coupled at a second end of the hollow core;
a window at the inlet optically coupled to the waveguide at the first end;
a mirror at the outlet optically coupled to the waveguide at the second end;
a first conduit configured to couple a fluid to the inlet; and
a second conduit configured to couple the fluid to the outlet.
2 . The flow cell according to claim 1 , wherein the first conduit and the second conduit are fluidly coupled to a pump.
3 . The flow cell according to claim 2 , wherein the pump is configured to cause a flow through the hollow core between the window and the mirror.
4 . The flow cell according to claim 3 , wherein the flow is from the first end to the second end, or from the second end to the first end.
5 . The flow cell according to claim 1 , wherein an index of refraction n f of the fluid is larger than an index of refraction n m of a material defining the hollow core of the waveguide.
6 . The flow cell according to claim 5 , wherein the index of refraction n f of the fluid is between 1.3 and 1.4.
7 . The flow cell according to claim 5 , wherein the index of refraction n m of the material is 1.29 at 785 nm.
8 . The flow cell-according to claim 1 , wherein an inner diameter of the hollow core is larger than 100 μm.
9 . The flow cell according to claim 8 , wherein the inner diameter is between 500 μm and 1000 μm.
10 . The flow cell according to claim 1 wherein a length of the waveguide is between 15 and 25 cm.
11 . The flow cell according to claim 1 , wherein the flow cell is configured to reversibly couple to a spectrometer.
12 . The flow cell according to claim 1 , wherein the flow cell is configured to reversibly couple to a Raman spectrometer.
13 . The flow cell according to claim 1 further including a lens configured to focus a light beam at the first end 106 of the waveguide.
14 . A method of analyzing a liquid sample comprising:
connecting an optical spectrometer to the flow cell according to claim 1 ;
flowing the fluid through the flow cell;
injecting an excitation light into the flow cell through the window;
extracting sample light from the flow cell through the window; and
providing the sample light to the spectrometer for analysis of the fluid sample.
15 . The method according to claim 14 , wherein the fluid flows through the waveguide from the first end to the second end, or the fluid flows through the waveguide from the second end to the first end.
16 . The method according to claim 14 , wherein the fluid includes water.
17 . The method according to claim 14 , wherein the fluid includes particles smaller than 100 μm.
18 . The method according to claim 14 , wherein the fluid includes biological cells.
19 . The method according to claim 14 , wherein the first conduit is fluidly connected to a reactor.
20 . The method according to claim 14 , wherein the optical spectrometer is a Raman spectrometer.
21 . A system for in-line monitoring of a fluid process, comprising:
a waveguide having a hollow core defined between a first end and a second end of the waveguide;
a window optically coupled at the first end and configured to transmit light into and out of the hollow core;
a mirror optically coupled at the second end of the waveguide and configured to reflect light towards the first end;
an inlet fluidly coupled at the first end to the hollow core and an outlet fluidly coupled at the second end to the hollow core;
a first conduit fluidly coupling a reactor to the inlet;
a second conduit fluidly coupling the outlet to the reactor; and
a spectrometer optically coupled to the waveguide.
22 . The system according to claim 21 , wherein the reactor is a bioreactor.