Fibre-optical microstructure Michelson interference SPR chemical and biological sensor and system

Abstract

The invention discloses an optical fiber microstructure Michelson interference type surface plasmon resonance chemical and biological sensor and system. The sensor is composed of a long-period optical fiber grating on an optical fiber, a reflection film on the cut surface of the optical fiber, an optical fiber cladding, an optical fiber core, A layer of metal film on the surface of the optical fiber cladding forms a surface plasmon resonance sensor with a fiber Michelson interferometer structure. The sensor integrates the functional devices and optical paths required by the Michelson interferometer, the metal film for surface plasmon resonance sensing, and the chemical or biomolecular sensitive film layer on a section of optical fiber. The entire sensor is completely optical fiber, miniaturized, and small in size. . The sensing system is composed of broadband light source, optical fiber, optical fiber microstructure Michelson interference surface plasmon resonance chemical and biological sensor, broadband coupler, optical fiber spectrometer and computer. The system can realize telemetry based on the optical fiber link, the system structure is simple, it is not affected by stray light, and the test results are stable and reliable.

Description

technical field [0001] The invention belongs to the field of optical fiber sensing, chemistry and biotechnology, and in particular relates to an optical fiber microstructure Michelson interference surface plasmon resonance (SPR) chemical and biological sensor and system. Background technique [0002] Optical fiber biological and chemical sensor is a new type of sensing technology that was born in the mid-1970s. , nucleic acid, DNA, animal and plant tissues or cells, microorganisms, polymer materials and other sensitive membranes, sol-gel or itself, adsorbed, solidified or installed on optical fibers, planar optical waveguides, capillary waveguides, and detect substances in samples Carry out selective identification, and then convert it into various optical information, such as signal output of ultraviolet, visible and infrared light absorption, reflection, fluorescence, phosphorescence, chemiluminescence and bioluminescence, Raman scattering, photoacoustic and surface plasmo...

AI Technical Summary

Problems solved by technology

[0016] There are also some defects in this type of sensor and system: (1) The prism-type sensor head is complex and bulky

The production of the optical fiber sensor head is cumbersome and difficult, and the cladding needs to be removed by chemical corrosion or mechanical abrasion, and the removal position or size of the cladding is difficult to precisely control

It is also difficult to fabricate a metal diffraction grating type sensor head

(2) The stability of the system is poor: whether it is wavelength modulation or angle modulation method, the signal detected directly is the light intensity, and it is the light intensity of a single optical path

The fluctuation and interference of the light source, optical path and circuit system have a great impact on the sensing system, reducing the reliability and accuracy

In the existing single light path intensity detection, this effect is difficult to eliminate

(3) Strong stray light interference: In the three SPR sensors of prism type, metal grating type and fiber optic type, stray light can enter the optical path and detector

(4) For fiber optic sensors, after chemical corrosion or mechanical abrasion of the cladding, there will be a rough interface, and it is difficult to obtain a smooth optical surface of the fiber core, which will affect the total reflection characteristics irregularly and generate large noise signals. Significantly reduced signal-to-noise ratio

(5) The data has no fault tolerance: the data obtained by the existing sensing system has no redundant information, and when there is a large interference and error, it will seriously affect the accuracy of the test or analysis results

(6) Weak telemetry capability: Prism-type and metal grating-type SPR sensors are difficult to achieve telemetry through optical fibers; at present, the optical fibers used in fiber-optic SPR sensors are mainly multi-mode fibers with large core diameters (small-core-diameter optical fiber sensors are difficult to manufacture, or even impossible) Production), generally only use a section of optical fiber of about tens of centimeters as the sensing head, it is difficult to make full use of the advantages of optical fiber

(7) The structure of the sensing system is complex and huge, and the operation is not flexible enough. Both the prism type and the metal grating type SPR sensor need a flow cell

The environmental adaptability is poor, the temperature change has a great influence on the test results, and the interference from the external vibration is also great, so it is very difficult to align and debug, and the same is true for the existing optical fiber sensors

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