Device for collecting fluorescent light emitted by particles in a medium
Inventors
Assignees
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Publication Number
US-11686682-B2
Publication Date
2023-06-27
Expiration Date
Abstract
There is provided a device (300;500;700) for collecting fluorescent light (322) emitted by particles (304) in a medium (302). The device (300;500;700) comprises a substrate (308) having a chamber (306) for holding the medium (302) including the particles (304) being capable of emitting fluorescent light (322). A first waveguide (310), which is arranged to receive and guide excitation light along a first direction (313), extends through the chamber (306). Fluorescent light (322) emitted by the particles (304) following an excitation is collected by the first waveguide (310). The device (300;500;700) further comprises a coupler (316;516) which includes a second waveguide (317) arranged to output collected fluorescent light (326) at one of its ends (318). The second waveguide (317) is arranged in relation to the first waveguide (310) such that collected fluorescent light (324) travelling in a direction opposite to the first direction (312) is coupled out from the first waveguide (310) directly into the second waveguide (317).
Core Innovation
A photonic integrated device collects fluorescent light emitted by particles in a medium using a substrate with a chamber for holding the medium. A first waveguide extends into the chamber, receives excitation light from a light source, guides the excitation light through the chamber along a first direction, and collects fluorescent light emitted by the particles following excitation by the excitation light.
A coupler arranged at the first waveguide is configured as a directional coupler including a second waveguide. The second waveguide outputs collected fluorescent light at one of its ends, and is arranged relative to the first waveguide so that collected fluorescent light travelling in a direction opposite to the first direction is coupled out from the first waveguide directly into the second waveguide, while excitation light coupled into the second waveguide is output at another end.
The detection approach uses the integrated waveguides and coupler to route collected fluorescent light without relying on bulky excitation/fluorescence rejection filters. Embodiments include a directional coupler with measurable coupler loss, a wavelength splitter for wavelength-based separation to reduce excitation back-contamination, and multi-mode interference coupler or wavelength-selective multi-mode interference to provide tolerance-insensitive and broadband or wavelength-selective operation. Saturation behavior is described such that waveguide length is independent of particle concentration.
Claims Coverage
The document includes two independent claims: one directed to a device structure for collecting and routing fluorescent light using a directional coupler, and another directed to a corresponding method for detecting fluorescent light and determining directional coupler loss. Across the independent claims, there are 4 main inventive features in claim-level coverage: an excitation/collection first waveguide through a chamber, a directional coupler with a second waveguide arranged for opposite-direction routing, detection at an end of the second waveguide, and determining directional-coupler loss from detected fluorescent-light power relative to excitation-light power.
Excitation and fluorescence collection in a chamber via a first waveguide
A substrate having a chamber for holding a medium including particles capable of emitting fluorescent light; and a first waveguide arranged at the substrate and extending into the chamber, arranged to receive excitation light and guide excitation light through the chamber along a first direction, and to collect fluorescent light emitted by the particles following excitation by the excitation light
Directional coupler routing oppositely traveling collected fluorescence into a second waveguide
A directional coupler arranged at the first waveguide, including a second waveguide arranged to output collected fluorescent light at one of its ends, arranged relative to the first waveguide such that collected fluorescent light travelling in a direction opposite to the first direction is coupled out from the first waveguide directly into the second waveguide and to output collected fluorescent light at a first end, and excitation light, coupled into the second waveguide from the first waveguide, at a second end
Detection of collected fluorescent light at an end of the second waveguide
Detecting, using a detector, the collected fluorescent light at one of the ends of the second waveguide
Determining directional coupler loss from detected power relative to excitation power
Detecting light at a second end of the second waveguide, and determining a loss of the directional coupler based on a power of the detected light in relation to a power of the excitation light received by the first waveguide
Overall, claim coverage centers on using a first waveguide through a chamber to collect excitation-induced fluorescence, then directly coupling collected fluorescence travelling in the opposite direction into a second waveguide via a directional coupler for detection, with an additional capability to determine directional coupler loss by comparing detected light power to excitation-light power.
Stated Advantages
Avoiding bulky excitation/fluorescence rejection filters.
Reduced excitation back-contamination using wavelength-based separation in wavelength splitter embodiments.
Tolerance-insensitive and broadband or wavelength-selective operation using multi-mode interference coupler or wavelength-selective multi-mode interference embodiments.
Waveguide length independence from particle concentration due to saturation behavior.
Documented Applications
Diagnostic use of the device in a diagnostic arrangement for fluorescent detection, including determining directional-coupler loss by power comparison.
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