Tapered multimode interference-based high-sensitivity optical fiber methane sensing device

A multi-mode interference, multi-mode optical fiber technology, applied in the field of high-sensitivity optical fiber methane sensing, can solve the problems of low sensitivity, low sensor sensitivity, changing the structure of the sensitive film, etc., and achieve the effect of high response speed and high porosity

Active Publication Date: 2015-12-02
重庆科知源科技有限公司
View PDF11 Cites 17 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the sensitive films of these methods are derived from the coating of cage molecules mixed with polysiloxane and styrene-acrylonitrile resins. Most of the cage molecules are wrapped in the film materials, and methane molecules are prone to appear in these films. Due to the problems of high migration resistance in the material and difficulty in contact with cage molecules, the response s

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Tapered multimode interference-based high-sensitivity optical fiber methane sensing device
  • Tapered multimode interference-based high-sensitivity optical fiber methane sensing device
  • Tapered multimode interference-based high-sensitivity optical fiber methane sensing device

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0050]Example 1: A SMF-MMF-SMF structure is formed by splicing a section of multimode fiber MMF and two sections of single-mode fiber SMF-28, the length of the multimode fiber is 42mm, the tapered area of ​​the multimode fiber after tapering is 0.68mm, and the beam waist diameter is 30μm ; After the surface of the tapered area is pre-coated with a nano-coating layer of silane coupling agent, the α-hydrogen-ω-hydroxy-polydimethylsiloxane containing cage molecule A is coated with a thickness of 350 nm along the surface of the tapered fiber. Methane sensitive films and porous. Taking the methane standard gas with a concentration of 0-3.5% (v / v) as the object, it interacts with the sensitive film on the surface of the optical fiber, and the characteristic wavelength of the transmission interference spectrum moves to the short wavelength direction with the increase of the methane gas concentration, and the transmission interference spectrum Shift Δλ of the characteristic wavelength...

Example Embodiment

[0055] Example 2: The experiment adopts a tapered optical fiber methane sensor with a tapered area of ​​0.55 mm, a beam waist diameter of 25 μm and a sensitive film thickness of 380 nm, and uses a known concentration of 0, 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5% (v / v) methane standard gas is used for detection, and the characteristic wavelength of the corresponding transmission interference spectrum trough moves to the short wavelength direction with the increase of methane gas concentration, and its interference spectrum trough characteristic wavelength shift amount Δλ c They are 0, 0.42, 0.82, 1.24, 1.62, 2.02, 2.48, 3.02, 3.48nm, respectively, and the linear regression equation is: Δλ c =0.9246c+0.2293, the correlation coefficient R 2 =0.9916, that is, k and b in the linear regression equation are 0.9242 and 0.2293, respectively.

[0056] When the methane gas to be tested is in contact with the sensor, the characteristic wavelength shift Δλ of the trough of the transmissio...

Example Embodiment

[0057] Example 3: A tapered optical fiber methane sensor with a tapered area of ​​0.76 mm, a beam waist diameter of 32 μm and a sensitive film thickness of 330 nm was used, and the known concentrations were 0, 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 %(v / v) methane standard gas is detected, the characteristic wavelength of the corresponding transmission interference spectrum trough moves to the short wavelength direction with the increase of methane gas concentration, and the characteristic wavelength of the interference spectrum trough is shifted by Δλ c They are 0, 0.42, 0.88, 1.24, 1.72, 2.16, 2.32, 3.04, 3.46nm, respectively. The linear regression equation is: Δλ c =0.9115c+0.2654, the correlation coefficient R 2 =0.9846, that is, k and b in the linear regression equation are 0.9115 and 0.2654, respectively.

[0058] When the methane gas to be tested is in contact with the sensor, the characteristic wavelength shift Δλ of the trough of the transmission interference spectrum...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Film thicknessaaaaaaaaaa
Login to view more

Abstract

The invention discloses a tapered multimode interference-based high-sensitivity optical fiber methane sensing device. The device comprises a broadband light source, a STMS-structure tapered multimode porous sensitive film-coated optical fiber sensing device, a testing air chamber, a switch valve, a mass flow controller, a spectrum analyzer and a computer. The STMS-structure optical fiber sensing device is prepared by single-mode optical fiber-multimode optical fiber-single-mode optical fiber melting connection and then multimode optical fiber tapering. The outer surface of the tapered multimode optical fiber is pre-treated by a silane coupling agent. The sensitive film is a cage molecule A-containing alpha-hydro-omega-hydroxy-polydimethylsiloxane porous methane-sensitive film. When methane gas to be detected reacts with the porous methane-sensitive film, a sensitive film refractive index is fast changed so that sensor interference spectrum characteristic wavelength lambda c is moved. Through analysis of interference spectrum characteristic wavelength movement amount delta lambda c before and after contact between the sensor and methane gas, a concentration of methane to be detected is obtained. The device has the characteristics of high sensitivity, fast response speed, good selectivity and good stability.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to a high-sensitivity optical fiber methane sensing method and device for obtaining methane concentration through conical multi-mode interference. Background technique [0002] With the rapid development of optical fiber sensing technology, the research of optical fiber gas sensor has received widespread attention. It is suitable for inflammable and explosive environments in harsh environments because of its good electrical insulation, anti-strong electromagnetic interference, explosion-proof, and long-distance long-term online measurement. Gas monitoring. [0003] Single-mode fiber (SMF)-tapered multimode fiber (TMMF)-single-mode fiber (SMF) structure (STMS) is a fiber structure based on the mode interference mechanism of tapered multimode fiber, which is embedded by a section of multimode fiber It is made by tapering multimode fiber after reaching a sect...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01N21/45
Inventor 杨建春王开武周浪车鑫陈伟民
Owner 重庆科知源科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap