阅读说明：本技术 一种空腔悬浮通道型光纤线上马赫-曾德干涉仪 (Mach-Zehnder interferometer on a kind of cavity suspension channel-style optical fiber cable ) 是由 王东宁 崔鑫磊 于 2019-10-10 设计创作，主要内容包括：本发明提供了一种空腔悬浮通道型光纤线上马赫-曾德干涉仪,包括宽带光源,传感头,光谱分析仪。其中传感头是由飞秒激光在两端单模光纤端面刻写微环并使其熔融对接构成。其特征是：飞秒激光刻写微环结构,熔接放电产生的高温使环形结构内的空气膨胀,进而挤压纤芯形成空腔内悬浮通道。由于通道尺寸极细约3μm,一部分光沿通道传输,一部分从空气腔中传输,最后两束光耦合回单模纤芯。宽带光源的光通过传感头传输至光谱分析仪,形成马赫-曾德干涉仪,测量透射光谱特征峰的波长或者强度漂移量,可计算出被测环境参数。本发明具有装置坚固、制备简单等特点,可用于温度、应变、气压、湿度、折射率测量。(The present invention provides Mach-Zehnder interferometer on a kind of cavity suspension channel-style optical fiber cable, including wideband light source, sensing head, spectroanalysis instruments.Wherein sensing head is to inscribe micro-loop in both ends single mode optical fiber end face by femtosecond laser and constitute its butt-fusion.It is characterized in that: femtosecond laser inscribes micro-loop structure, the high temperature that welding electric discharge generates expands the air in ring structure, and then squeezes fibre core and form suspension channel in cavity.Due to superfine about 3 μm of channel size, a part of light is transmitted from air chamber along channel transfer, a part, and last two-beam is coupled back into fiber core with single-mold.The light of wideband light source is transmitted to spectroanalysis instrument by sensing head, forms Mach-Zehnder interferometer, measures the wavelength or intensity drift amount at transmission spectral signatures peak, can calculate test environment parameter.The present invention has the characteristics that device is firm, it is simple to prepare, and can be used for temperature, strain, air pressure, humidity, refractometry.)

1. Mach-Zehnder interferometer on a kind of cavity suspension channel-style optical fiber cable, including wideband light source, sensing head, spectrum analysis Instrument, connection type are as follows: sensing head one end is connect with wideband light source, and the other end is connected with spectroanalysis instrument；It is characterized by: Femtosecond laser inscribes micro-loop structure, and the high temperature that welding electric discharge generates expands the air in ring structure, and then squeezes fibre core shape At the channel that suspends in cavity.

2. Mach-Zehnder interferometer device on a kind of cavity suspension channel-style optical fiber cable, feature exist according to claim 1 In: femtosecond laser inscribes micro-loop structure, two micro-loop structure butt-fusions, and the high temperature that welding electric discharge generates makes in ring structure Air expansion, and then squeeze fibre core and form suspension channel in cavity, since channel size is superfine, a part of light along channel transfer, A part is transmitted from air chamber, and last two-beam is coupled back into fiber core with single-mold.

3. according to claim 1 on a kind of cavity suspension channel-style optical fiber cable Mach-Zehnder interferometer sensor device, It is characterized in that: its core diameter of the single mode optical fiber and fibre diameter are respectively 9 μm and 125 μm；Fiber core refractive index is 1.4682； Cavity length is about 50 μm consistent with suspension passage length；About 3 μm of suspension channel diameter in cavity.

Technical field

The present invention provides Mach-Zehnder interferometers on a kind of cavity suspension channel-style optical fiber cable, belong to Fibre Optical Sensor skill Art.

Background technique

Fibre optical sensor is for traditional sensors, and with high sensitivity and resolution ratio, frequency range is very Width, dynamic range is very big, not by the interference of electromagnetic field the advantages that, in recent years defense military portion, scientific research department and process industry, Practical application is all obtained in the field of scientific studies such as energy industry, medical treatment.The development trend of sensor is sensitive, accurate, applicable Property is strong, small and exquisite and intelligent.In numerous fibre optical sensors, the fibre optical sensor based on Mach-Zehnder is quickly grown, and is become One important branch of fibre optical sensor research field, is widely used in structure internal strain, stress, temperature, pressure, deformation, vibration The continuous real-time safety detection of the physical quantitys such as dynamic and displacement, it may also be used for the monitoring etc. of the solid state of composite material.For flying The safe handlings such as machine, naval vessel, building and integrity detection are of great significance.Currently, various novel Mach-Zehnder interferometers And preparation method thereof also emerge one after another, such as based on internal micro- conical fiber with cavity, the optical fiber of dislocation welding, fiber grating With special optical fiber etc..The above has very big deficiency, and built-in air cavity equipment is very fragile, less robust；Fiber core dislocation is molten It connects its repeatability to be difficult to realize, and assembled by hand needs the plenty of time；Fiber grating writing process is complicated, higher cost, and The unstability of its structure limits its application to a certain extent；Special fiber is expensive.In addition, their free spectrum Range (FSR) is difficult to control accurately.In order to overcome these disadvantages, it would be desirable to make fibre optical sensor using new technology Part.

Interferometer is a kind of attractive miniature and multifunctional optical fiber sensing equipment with high sensitivity on optical fiber cable, The online interferometer configurations of various types of optical fiber, such as Fabry-Perot interferometer (FPI) are developed, Michelson is dry Interferometer (MI) and Mach-Zehnder interferometer (MZI).MZI manufacture is relatively easy, flexible structure, and sensitivity is high.Optical fiber is online MZI mainly by using LPFG to, optical fiber taper, unmatched fibre core and the sandwich structure being made of SMF and hollow fibre At.In this configuration, optical fiber core model and cladding mode generate interference, propagate along almost the same path length.Due to optical fiber Refractive index (RI) difference very little between core model and cladding mode, the size of interferometer is quite big, freedom especially small when needs When spectral region (FSR) Lai Tigao device sensitivity.The effective of compact apparatus size is realized while keeping it highly sensitive Mode is using the MZI based on open air chamber, this is because the big RI difference between fibre core and air.But it is because logical It crosses laser micromachined and eliminates few fibers material, the difficulty of such MZI device is less robust.

Summary of the invention

The present invention in view of the shortcomings of the prior art, provide Mach-Zehnder interferometer on a kind of cavity suspension channel-style optical fiber cable, Device is firm, prepares feature simple, at low cost, small in size, can be applied to the survey of temperature, strain, air pressure, humidity, refractive index Amount.

A kind of technical solution adopted for solving the technical problem of the present invention are as follows: Mach-on cavity suspension channel-style optical fiber cable Zehnder interferometer, including wideband light source, sensing head, spectroanalysis instrument, connection type are as follows: sensing head one end and wideband light source connect It connects, the other end is connected with spectroanalysis instrument；It is characterized by: femtosecond laser inscribes micro-loop structure, two micro-loop structure meltings Docking, the high temperature that welding electric discharge generates expand the air in ring structure, and then squeeze fibre core and form suspension channel in cavity. Since channel size is superfine, surplus size is 3 μm much smaller than former 9 μm of core diameter of single mode optical fiber, therefore a part of light is along logical Road transmission, a part are transmitted from air chamber, and last two-beam is coupled back into fiber core with single-mold, to form Mach-Zehnder interferometer institute The transmission spectrum needed.

Its core diameter of (single mode) optical fiber and fibre diameter are respectively 9 μm and 125 μm.

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

1, sensing head selects cheap general single mode fiber, the advantage for having production simple, at low cost.

2, sensing head all has temperature, stress, refractive index, air pressure, humidity different sensibility, can be used for ring It is measured while the parameter of border.

3, sensing head comparatively robust maintains the slickness and uniformity of optical fiber surface after welding, have symmetrical well Property.

4, the production of sensing head is easily controllable, and the radius and depth and molten of cyclic structure can be inscribed by control femtosecond It picks the electricity of welding and the time controls the size of cavity and inner passage, and then can control sensing head Free Spectral Range (FSR)。

Detailed description of the invention

In order to illustrate the embodiments of the present invention more clearly or technical solution, the present invention is made with reference to the accompanying drawings and examples It further illustrates.

Fig. 1 practices system schematic for of the invention.

Fig. 2 is the present invention in single mode optical fiber surface femtosecond inscription partial structure diagram.

Fig. 3 is final structure complete diagram of the present invention.

In figure, 1. wideband light sources, 2. sensing heads, 3. spectroanalysis instruments, 4. single mode optical fibers, 4 (a) single mode optical fiber fibre cores, 4 (b) single mode optical fiber covering, 5. annular grooves, 6. single mode optical fibers, 6 (a) single mode optical fiber fibre cores, 6 (b) single mode optical fiber coverings, 7. Air chamber, microchannel in 8. air chambers.

Specific embodiment

With reference to the accompanying drawing and embodiment the invention will be further described:

Fig. 1 show the system schematic that practices of the invention, including wideband light source 1, sensing head 2, spectroanalysis instrument 3.Its connection type are as follows: wideband light source 1 is connect with one end of sensing head 2, and the other end of sensing head 2 is connected with spectroanalysis instrument 3 It connects.

Fig. 2 show the structural schematic diagram of sensing head 2 of the present invention in femtosecond processing preparation process, is specially cutting flat with On single mode optical fiber end face, away from the annular groove for inscribing 3 μm of width, 6 μm of depth at 15 μm of fibre core.The structure includes by single mode optical fiber 4 Single mode optical fiber covering 4 (a) and single mode optical fiber fibre core 4 (b), annular groove 5 are constituted.

Fig. 3 show the final structure schematic diagram of sensing head 2 of the present invention, which is molding final after heat sealing machine welding Structure includes single mode optical fiber covering 6 (a) and single mode optical fiber fibre core 6 (b), air cavity configuration 7, intracavitary microchannel by single mode optical fiber 6 Structure 8 forms

The production method and step of the sensing head 2 are: step 1: it is flat that the single mode optical fiber cut flat with is placed in femtosecond processing On platform, finds optical fiber midpoint and determine focal plane；Second step inscribes ring structure by the center of circle of optical fiber midpoint, and the circular ring structure is wide 3 μm of degree, obtains structure shown in Fig. 2 by 3 μm of depth；Third step, ultrasonic cleaning Fig. 2 ring structure make inside it without residue；4th Step: by two identical Fig. 2 structure welding.

In conjunction with Fig. 1,2,3, introduce specific working principle: sensing head 2 inscribes the sky formed in conjunction with melting behaviors by femtosecond Chamber suspension channel design, sensing head 2 receive the light beam issued from wideband light source 1, this light beam a part is directed by microchannel Enter fibre core, another part spreads into fibre core from air chamber, to form the output spectrum of Mach-Zehnder interferometer.

Particular embodiments described above has carried out further in detail the purpose of the present invention, technical scheme and beneficial effects It describes in detail bright, it should be appreciated that, the above is only a specific embodiment of the present invention, is not intended to restrict the invention, all Within the spirit and principles in the present invention, any modification, equivalent substitution, improvement and etc. done should be included in guarantor of the invention Within the scope of shield.