CN109708775A

CN109708775A - The temperature of photonic crystal fiber FP-FBG structure, index sensor and preparation method thereof

Info

Publication number: CN109708775A
Application number: CN201910059621.XA
Authority: CN
Inventors: 祝连庆; 周康鹏; 何巍; 张雯; 娄小平; 董明利; 宋言明
Original assignee: Beijing Information Science and Technology University
Current assignee: Beijing Information Science and Technology University
Priority date: 2019-01-22
Filing date: 2019-01-22
Publication date: 2019-05-03

Abstract

The invention discloses the temperature and index sensor of a kind of photonic crystal fiber FP-FBG structure, including photonic crystal fiber, it is characterized in that, central wavelength is the fiber bragg grating structure of 1550nm there are three setting on the fibre core of the photonic crystal fiber, three fiber bragg grating structures are between any two at a distance of 1000 μm, long 50 μm, 80 μm wide, the entire cross section of depth penetration slot are scribed using by-line method using femtosecond laser in the middle position of wherein two fiber bragg gratings, the sensing of temperature and refractive index is carried out using the reflectance spectrum figure of the structure.

Description

Temperature, index sensor and its production of photonic crystal fiber FP-FBG structure Method

Technical field

The invention belongs to field of fiber optics, temperature, refractive index more particularly to photonic crystal fiber FP-FBG structure Sensor and preparation method thereof.

Background technique

Fibre optical sensor is with many good characteristics, it can be achieved that the measurement work under complex environment has very extensive answer With value.It has the characteristics that electromagnetism interference, anti-radiation, high sensitivity, light-weight, insulation explosion-proof, corrosion-resistant, and fiber optic ruler It is very little small, there is good optical transmission performance.In various types of fibre optical sensors, it is interference-type light that precision is highest at present Fiber sensor.Wherein optical fiber FP sensor (Fabry-Pérot sensor) is because only with an optical fiber and structure is simply small in size, dynamic State range is big, receives significant attention in biomedicine, magnetic field, MEMS.

Optical fiber FP sensor mainly includes extrinsic type and Intrinsical two major classes.The optical fiber FP sensor of extrinsic type structure Be to be formed using optical fiber and one with the non-optical fiber original part of reflecting surface structure；The processing method one of Intrinsical optical fiber FP structure As to form a pair of of high reflection mirror, and then coelosis by plated film, the change means such as refractive index using on optical fiber.

Summary of the invention

The present invention is achieved through the following technical solutions:

A kind of temperature and index sensor of photonic crystal fiber FP-FBG structure, including photonic crystal fiber, the photon Central wavelength is the fiber bragg grating structure of 1550nm there are three setting on the fibre core of crystal optical fibre, three optical fiber Bragg light Grid structure between any two at a distance of 1000 μm, the middle position of wherein two fiber bragg gratings using femtosecond laser use by Collimation method scribes long 50 μm, 80 μm wide, the entire cross section of depth penetration slot, using the reflectance spectrum figure of the structure carry out temperature and The sensing of refractive index.

Further to improve, the temperature and index sensor use wideband light source as light source.

A kind of production method of the temperature and index sensor of photonic crystal fiber FP-FBG structure, including walk as follows It is rapid:

Step 1) it will be clean with alcohol wipe after photonic crystal fiber removal coat；

Step 2) photonic crystal fiber is fixed in three-dimensional mobile platform；Femtosecond laser is focused on fibre core, perpendicular to light It is fine axial, it uses point by point method to write on fibre core and produces 3 central wavelengths as the fiber bragg grating of 1550nm, three optical fiber cloth Glug optical grating construction is between any two at a distance of 1000 μm；

Step 3) it is scribed using femtosecond laser using by-line method in the middle position of wherein two fiber bragg gratings and grows 50 μ M, wide 80 μm, the slot of the entire cross section of depth penetration utilize the reflectance spectrum figure of the structure to carry out the sensing of temperature and refractive index

Compared with prior art, the invention has the following advantages that

All -fiber is used using the FP temperature sensor based on photonic crystal fiber of technical method provided by the present invention production Formula structure can avoid influence of the electromagnetic interference to testing result.The sensor reliability is high simultaneously, and when use only need to be by sensor Place is partially disposed in environment to be measured, and building for test macro can be completed in other end connection spectrometer, by anti-through sensor The mode for penetrating the free spectrum width of spectrum detects temperature change, high sensitivity.

Detailed description of the invention

Fig. 1 is the FP chamber schematic diagram that a FBG structure is formed;

Fig. 2 is FBG machining sketch chart；

Fig. 3 is temperature-spectrum data gathering schematic diagram

Fig. 4 is the received reflectance spectrum of this spectroanalysis instrument.

Specific embodiment

In order to make those skilled in the art more fully understand technical solution of the present invention, and make features described above of the invention, Purpose and advantage are more clear understandable, are further explained explanation to the present invention now in conjunction with embodiment, it is noted that herein All embodiments listed are merely illustrative, are not meant to be defined the scope of the invention.

Embodiment 1:

Photonic crystal fiber coat is removed, is fixed in three-dimensional mobile platform after alcohol wipe；It is point-by-point using femtosecond laser Method progress FBG's writes system；The FBG that three central wavelengths are 1550nm is inscribed on optical fiber, is spaced 1000 μm, constitutes FP chamber；? It is scribed using by-line method at 500 μm using femtosecond laser among two FBG 50 μm long, 80 μm wide, the entire cross section of depth penetration Slot carries out temperature, refractometry.

Optical fiber temperature sensor detection temperature system of the invention is as shown in Figure 3.Fibre optical sensor be immersed in fill it is to be measured molten In the beaker of liquid, beaker is placed on heating platform, is connected by fiber optical circulator with optical fiber sensing analyzer.Spectral analysis apparatus The spectroanalysis instrument for having used Yokogawa company to produce carries out the acquisition of reflectance spectrum in this experiment；Fiber optical circulator makes Optical fiber sensing analyzer is transmitted to the reflection interference spectrum of fiber F-P cavity.It is reflected by changing beaker solution refractive index Rate test；Temperature by changing heating platform carries out temperature test.

Reflectance spectrum in experiment is as shown in Figure 3.When ambient temperature changes, reflectance spectrum spectral line can drift about, Recording certain characteristic peak corresponding wavelength value under different temperatures, refractive index can be realized high-acruracy survey to temperature.

Claims

1. a kind of temperature and index sensor of photonic crystal fiber FP-FBG structure, including photonic crystal fiber, feature Be, set on the fibre core of the photonic crystal fiber there are three central wavelength as the fiber bragg grating structure of 1550nm, three A fiber bragg grating structure utilizes between any two at a distance of 1000 μm in the middle position of wherein two fiber bragg gratings Femtosecond laser scribes long 50 μm, 80 μm wide, the entire cross section of depth penetration slot using by-line method, utilizes the reflected light of the structure The sensing of spectrogram progress temperature and refractive index.

2. special such as its a kind of temperature and index sensor of photonic crystal fiber FP-FBG structure described in claim 1 Sign is that the temperature and index sensor use wideband light source as light source.

3. the production method of the temperature and index sensor of a kind of photonic crystal fiber FP-FBG structure, which is characterized in that packet Include following steps:

Step 3) it is scribed using femtosecond laser using by-line method in the middle position of wherein two fiber bragg gratings and grows 50 μ M, wide 80 μm, the slot of the entire cross section of depth penetration utilize the reflectance spectrum figure of the structure to carry out the sensing of temperature and refractive index.