Multi-analyte optical sensor

Patent metadata

Field	Value
Publication number	US-9671334-B2
Application number	US-201314437039-A
Country	US
Kind code	B2
Filing date	Oct 25, 2013
Priority date	Oct 25, 2012
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

An analyte-detection system has an optical waveguide with first and second cladding layers adjacent a core; a light source coupled to provide light to the waveguide; a photodetector such as a metal-semiconductor-metal, vertical PIN, or horizontal PIN photodetectors, the photodetector having an absorber configured to detect light escaping from the waveguide through the first cladding layer; multiple, separate, photocurrent collectors, where each photocurrent collector collects current from a separate portion of the photodetector absorber; and at least one current-sensing amplifier for receiving photocurrent. The photodetector absorber is an undivided absorber region for multiple photocurrent collectors. Either separate amplifiers are provided for each of the multiple photocurrent collection lines, or multiplexing logic couples selected photocurrent collectors to amplifiers, while coupling unselected photocurrent collectors to a bias generator.

First claim

What is claimed is:

1. An improved detection system of the type comprising:
an optical waveguide having first and second cladding layers adjacent to a core, the core transparent at a first wavelength;
a light source coupled to provide light of the first wavelength to the waveguide;
a photodetector having a photodetector absorber disposed near the first cladding layer, the photodetector absorber configured to detect light of the first wavelength escaping from the waveguide through the first cladding layer;
a plurality of separate photocurrent collection lines, where each photocurrent collection line is configured to collect current from a different portion of the photodetector absorber; and
at least one amplifier adapted to receive photocurrent;
the improvement comprising the photodetector absorber being configured as an undivided photoelectric absorber region for a plurality of the photocurrent collection lines; and
wherein the detection system is configured such that the light escaping from the waveguide through the first cladding layer is alterable by an analyte applied to the second cladding layer.

2. An improved detection system of the type comprising:
an optical waveguide having first and second cladding layers adjacent to a core, the core transparent at a first wavelength;
a light source coupled to provide light of the first wavelength to the waveguide;
a photodetector having a photodetector absorber disposed near the first cladding layer, the photodetector absorber configured to detect light of the first wavelength escaping from the waveguide through the first cladding layer;
a plurality of separate photocurrent collection lines, where each photocurrent collection line is configured to collect current from a different portion of the photodetector absorber; and
at least one amplifier adapted to receive photocurrent;
the improvement comprising the photodetector absorber being configured as an undivided absorber region for a plurality of the photocurrent collection lines,
and wherein the second cladding layer has at least a sensing portion configured to respond to presence of an analyte with a shift of refractive index, the portion configured to respond to an analyte comprising a first section lying over a portion of the photodetector absorber coupled to a first of the photocurrent collection lines.

3. The detection system of claim 2 wherein the second cladding layer has at least a portion configured as a reference section that has a lower response to presence of the analyte than the sensing portion, the portion configured as a reference section lying over a portion of the photodetector absorber coupled to a second of the photocurrent collection lines.

4. The detection system of claim 2 wherein the second cladding layer has a second sensing portion configured to respond to presence of a second analyte, the second sensing portion lying over a portion of photodetector absorber coupled to a third of the photocurrent collection lines.

5. An improved detection system of the type comprising:
an optical waveguide having first and second cladding layers adjacent to a core, the core transparent at a first wavelength;
a light source coupled to provide light of the first wavelength to the waveguide;
a photodetector having a photodetector absorber disposed near the first cladding layer, the photodetector absorber configured to detect light of the first wavelength escaping from the waveguide through the first cladding layer;
a plurality of separate photocurrent collection lines, where each photocurrent collection line is configured to collect current from a different portion of the photodetector absorber; and
at least one amplifier adapted to receive photocurrent;
the improvement comprising the photodetector absorber being configured as an undivided absorber region for a plurality of the photocurrent collection lines, and
wherein the second cladding layer is present in a reference section lying over a portion of the photodetector absorber coupled to a second of the photocurrent collection lines, and the second cladding layer is absent in a sensing section lying over a first of the photocurrent collection lines.

6. The detection system of claim 1 wherein each current-sensing amplifier of a plurality of the current sensing amplifiers is configured to receive photocurrent from a separate photocurrent collection line of the photocurrent collection lines.

7. An improved detection system of the type comprising:
an optical waveguide having first and second cladding layers adjacent to a core, the core transparent at a first wavelength;
a light source coupled to provide light of the first wavelength to the waveguide;
a photodetector having a photodetector absorber disposed near the first cladding layer, the photodetector absorber configured to detect light of the first wavelength escaping from the waveguide through the first cladding layer;
a plurality of separate photocurrent collection lines, where each photocurrent collection line is configured to collect current from a different portion of the photodetector absorber; and
at least one amplifier adapted to receive photocurrent;
the improvement comprising the photodetector absorber being configured as an undivided absorber region for a plurality of the photocurrent collection lines, and
wherein at least one current-sensing amplifier is configured to receive photocurrent from analog multiplexing circuitry, the analog multiplexing circuitry configured to couple a first photocurrent collection line to the at least one current-sensing amplifier and a second photocurrent collection line to a bias line when a control input is in a first state, and the second photocurrent collection line to the at least one current-sensing amplifier and the first photocurrent collection line to the bias line when the control input is in a second state.

8. The detection system of claim 2 , 3 , 4 , 5 , or 7 wherein the first wavelength is between 200 and 5000 nanometers.

9. The detection system of claim 8 wherein the first wavelength is between 400 and 2000 nanometers.

10. The detection system of claim 8 wherein the photodetector is a metal-semiconductor-metal detector.

11. The detection system of claim 8 wherein the photodetector is a P-intrinsic-N (PIN) photodiode detector.

12. The detection system of claim 11 wherein the photodetector is a lateral PIN detector.

13. The detection system of claim 8 wherein the at least one amplifier adapted to receive photocurrent is a transimpedance amplifier.

14. An improved analyte-detection system comprising:
an optical waveguide having first and second cladding layers adjacent to a core, the core transparent at a first wavelength;
a light source coupled to provide light of the first wavelength to the core of the waveguide;
a photodetector selected from the group consisting of metal-semiconductor-metal, vertical PIN, and horizontal PIN photodetectors, the photodetector having an absorber disposed near the first cladding layer and configured to detect light escaping from the waveguide at the first wavelength; multiple, separate, photocurrent collection lines, where each photocurrent collection line is configured to collect current from a separate portion of the photodetector absorber; and at least one current-sensing amplifier for receiving photocurrent;
wherein the photodetector absorber is an undivided absorber region for multiple photocurrent collection lines; and
either separate amplifiers are provided for each of the multiple photocurrent collection lines or multiplexing logic couples N selected photocurrent collection lines to N amplifiers

Assignees

• Univ Colorado State Res Found

Inventors

• Lear Kevin L
• Erickson Timothy A

Classifications

• H01L31/105

  Electricity · mapped topic

• G01N2201/0833

  Fibre array at detector, resolving · CPC title

• G01N21/4133 Primary

  Refractometers, e.g. differential · CPC title

• G01N21/7703 Primary

  using reagent-clad optical fibres or optical waveguides (using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B) · CPC title

• G01N2021/7793

  Sensor comprising plural indicators · CPC title