Optoelectronic hybrid integration sensor device of sulfureted hydrogen gas concentration and method of testing thereof
Technical field
The present invention relates to a kind of optoelectronic hybrid integration sensor device of sulfureted hydrogen gas concentration and method of testing thereof, belong to sulfureted hydrogen gas concentration on-line monitoring instrument field, be specially adapted to the photoelectricity mixing integrated form gas concentration sensor of polymer optical wave guide and sulfuretted hydrogen reaction.
Background technology
Hydrogen sulfide gas is the great hypertoxic gas of a kind of harmfulness, and low concentration just can make the people fatal, is one of bigger pollutant of atmosphere pollution toxic.Hydrogen sulfide gas is mainly derived from the production runes such as steel-making, oil refining, papermaking, dyestuff, pharmacy and process hides, and it has the strong corrosion characteristic, and the heavy corrosion production equipment influences workers ' health.
Hydrogen sulfide gas has strong toxicity and corrosivity, sulfureted hydrogen gas concentration is detected adopt several different methods to study both at home and abroad, and its main research method is the photoelectrochemical method of electrochemical process, optical method and the two combination.Electrochemical process is to utilize the hydrogen sulfide gas molecule on the sensitive electrode of sensor electrochemical reaction to take place, and this reaction causes the output electric signal of sensor to change, and reflects the variation of gas concentration by the size of measuring the change value.Electrochemical process occurs the earliest, technology maturation, but it is low to be subjected to cross sensitivity to influence its precision.The most important detection method of optical method is a spectral absorption method, utilizes hydrogen sulfide gas to detect the concentration of hydrogen sulfide gas in the absorption characteristic spectrum of near-infrared band.This method has the strong advantage of fast, the anticorrosive anti-electromagnetic interference capability of reaction.But through the output intensity after the stink damp bulk absorption a little less than, detection sensitivity is very low, serious interference.
Photoelectrochemical method is the important method that detects sulfureted hydrogen gas concentration.It combines magnanimity, the advantage quick and anti-electromagnetic interference (EMI) with other compound reaction properties and fiber-optic signal transmission are had of hydrogen sulfide gas, realizes the remote safety detection of sulfureted hydrogen gas concentration.
Through to existing domestic and international open source literature report retrieval discovery, utilize optical waveguide to mix the document of integrated detection sulfureted hydrogen gas concentration: highly sensitive optical waveguide sensor detection H
2S gas (sensing technology journal .2007,20 (9) .-1937-1939): methyl green one polyvinyl alcohol film is fixed on potassium ion exchange glass optical waveguide surface forms methyl green one PVA film, do the time spent when film and hydrogen sulfide gas, cause the variation of propagates light evanescent field in the waveguide. detect these variations and can obtain sulfureted hydrogen gas concentration information.This method detects sulfuretted hydrogen with the variation of evanescent field, but evanescent field a little less than, signal to noise ratio (S/N ratio) is very little, can not realize the low concentration hydrogen sulphide gas detection.Owing to adopt prism structure to realize optically-coupled, stability of layout is poor simultaneously, and sensor is difficult to miniaturization.
Summary of the invention
The present invention seeks to provides a kind of photoelectricity to mix integrated sulfureted hydrogen gas concentration sensor at the deficiencies in the prior art, it is little to be characterized in solving in the low concentration hydrogen sulphide gas detection technology signal to noise ratio (S/N ratio), the problem that sensitivity is low, utilize optical waveguide to mix integrated technology simultaneously, make photoelectricity of the present invention mix little, the good stability of integrated sulfureted hydrogen gas concentration sensor bulk.
Purpose of the present invention is realized by following technical measures:
The laser that optoelectronic hybrid integration sensor device of sulfureted hydrogen gas concentration is drawn by laser instrument imports the polarized light that focuses in the gas box into through the volume device scioptics optical fiber that shakes, realize optical fiber and waveguide-coupled on the input coupling element, light after the coupling enters Mach-Zehnder (M-Z) Waveguide interference instrument, be connected in parallel with reference arm waveguide and signal arm waveguide respectively by branch-waveguide then, determine two Waveguide end face sizes by mould field coupling, to reduce coupling loss, improve coupling efficiency, Waveguide Phase Modulator is a lump type Waveguide Phase Modulator structure, be located between reference arm waveguide and the signal wave-guides, light after M-Z Waveguide interference instrument is interfered is coupled out gas box by the output coupling element, enter photosignal conversion and disposal system, by optical fiber lead-in light electric diode behind lens and analyzer, light intensity is converted into electric signal input micro-signal processor, obtains the concentration value of hydrogen sulfide gas to be measured through computing.
Polarizer is TE or TM polarization.
Coupling element is V-type groove end face butt joint coupling.
M-Z Waveguide interference instrument is at LiNbO
3Make on the crystal; The reference arm waveguide is Ni diffusion LiNbO
3Ridge waveguide, waveguide are the Ni/Ti/Si three-decker; The signal arm waveguide is a ferrocene-based polymer, and is made by the wet method photoetching corrosion.
One side of gas box is established the hydrogen sulfide gas import, and the opposite side of gas box is established the hydrogen sulfide gas gas outlet.
The method of testing of optoelectronic hybrid integration sensor device of sulfureted hydrogen gas concentration may further comprise the steps:
1, the optical maser wavelength that laser instrument is sent is that 620nm forms linearly polarized light behind polarizer, enter the sulfureted hydrogen gas concentration sensor-based system by Lens Coupling, hydrogen sulfide gas enters gas box from air intake opening, in Mach-Zehnder Waveguide interference instrument, propagate, signal arm reaction with interferometer, change the signal arm waveguide index, the variation of sulfureted hydrogen gas concentration is converted to light phase changes in the signal arm, again phase change is converted to light intensity and changes;
2, the light that light intensity is changed enters photosignal conversion and disposal system, and photodetector detects the light intensity variation and obtains corresponding electric signal, obtains the concentration value of tested hydrogen sulfide gas after signal processing unit processes;
3, stop to feed hydrogen sulfide gas after, the signal arm of Mach-Zehnder interferometer and the oxygen of lasting bubbling air carry out polymer reduction reaction.
Guarantee the sealing of gas in the whole testing process; The coupling of interferometer adopts end face butt joint coupling, and interferometer is divided into flashlight and interference light with light in the ratio of 1: 1 light intensity, transmits in signal arm and reference arm respectively.
The present invention has following advantage:
1, the present invention utilizes polymer optical wave guide and sulfuretted hydrogen to react the concentration that detects hydrogen sulfide gas, be whole wave guide and sulfuretted hydrogen the reaction and be not only the coat of waveguide surface, thereby what change is the light intensity of transmitting in the refractive index change whole wave guide of optical waveguide, it or not the evanescent field that changes waveguide surface, so the light intensity change that the sulfuretted hydrogen of same concentrations causes is more remarkable, has improved the detection sensitivity of low concentration hydrogen sulphide gas.
2, the present invention adopts the polymer waveguide of refractive index to the selective response of hydrogen sulfide gas, and with its signal arm as the M-Z interferometer, then hydrogen sulfide gas and the interaction of sensitive layer cause the variation of guided wave intensity (phase place). detect these variations and can obtain the relevant information of concentration of hydrogen sulfide, improved the selectivity of gas.
3, to adopt light-source system, opto-electronic conversion and disposal system to mix with the M-Z light guide interference integrated in the present invention, realized the miniaturization of whole sensor-based system, owing to adopt the light integrated technology, reduced light coupling loss simultaneously, improved system stability.Therefore, the present invention adopts light integrated technology and light sensing technology, and that the sulfureted hydrogen gas concentration sensor of design has is highly sensitive, good reversibility, reappearance height, cost are low, advantages such as simple in structure and easy making.
Description of drawings
Fig. 1 photoelectricity of the present invention mixes integrated sulfureted hydrogen gas concentration sensor synoptic diagram
1, laser instrument, 2,8 polarizers, 3,7 lens, 4, optical fiber, 5,19 branch-waveguides, 6, signal arm, 9, photodiode, 10, the micro-signal processor, 11, H
2The S air intake opening, 12, the input coupling element, 13, gas box, 14, M-Z Waveguide interference instrument, 15, reference arm, 16, Waveguide Phase Modulator, 17, H
2The S gas outlet, 18, output coupling element.
Embodiment
Below by embodiment the present invention is carried out concrete description; it is important to point out that present embodiment only is used for the present invention is further specified; can not be interpreted as limiting the scope of the invention, the person skilled in the art in this field can do some nonessential improvement and adjustment according to the content of the invention described above.
Concrete structure of the present invention as shown in Figure 1, light source of the present invention and polarisation system are made up of laser instrument 1, polarizer 2 and lens 3, laser instrument 1 output light wavelength is 620nm.Polarizer can be selected TE or TM polarization.
The sulfureted hydrogen gas concentration sensor-based system is made of M-Z Waveguide interference instrument and gas box, optical fiber 4 imports the polarized light that lens 3 focus on into gas box, realize the coupling of optical fiber and waveguide on input coupling element 12, input coupling element 12 can adopt V-type groove end face butt joint coupling.Light after the coupling enters M-Z Waveguide interference instrument 14, and M-Z Waveguide interference instrument 14 can be at LiNbO
3Make on the crystal: branch- waveguide 5,19 and reference arm waveguide 15 are made as Ni diffusion LiNbO
3Ridge waveguide, waveguide are the Ni/Ti/Si three-decker.Signal arm waveguide 6 can adopt the wet method lithography corrosion technology to make polymer waveguide, determines two Waveguide end face sizes by mould field coupling, reduces coupling loss and improves coupling efficiency.Waveguide Phase Modulator 16 is lump type Waveguide Phase Modulator structure.Light after the interference is coupled out gas box by output coupling element 18, and output coupling element 18 structures are consistent with input coupling element 12.
Gas box 13 can adopt inwall to do the aluminum alloy materials of corrosion-resistance treatment, hydrogen sulfide gas enters gas box 13 from air intake opening 11, with 17 outflows of polymer waveguide 6 reaction backs from the gas outlet, because the hypertoxicity of hydrogen sulfide gas, require gas box under the vacuum of-50KPa (gauge pressure), but pressurize 10 minutes.
Photosignal conversion and disposal system are made of lens 7, analyzer 8, photodiode 9, micro-signal processor 10.From the interference light that comes out of output coupling element 18 by optical fiber lead-in light electric diode 9 behind lens 7 and analyzer 8, the light intensity variation is converted in the electric signal input micro-signal processor 10, obtain sulfureted hydrogen gas concentration value to be measured through computing, also operation result can be imported computing machine.
The method of testing of optoelectronic hybrid integration sensor device of sulfureted hydrogen gas concentration may further comprise the steps:
1, the optical maser wavelength that laser instrument 1 is sent is that 620nm forms linearly polarized light behind polarizer 2, be coupled into the sulfureted hydrogen gas concentration sensor-based system by lens 3, hydrogen sulfide gas enters gas box 13 from air intake opening 11, in Mach-Zehnder Waveguide interference instrument 14, propagate, signal arm 6 reactions with interferometer, change the signal arm waveguide index, the variation of sulfureted hydrogen gas concentration is converted to light phase changes in the signal arm, again phase change is converted to light intensity and changes;
2, the light that light intensity is changed enters photosignal conversion and disposal system, and photodetector detects the light intensity variation and obtains corresponding electric signal, obtains the concentration value of tested hydrogen sulfide gas after signal processing unit processes;
3, stop to feed hydrogen sulfide gas after, the signal arm of Mach-Zehnder interferometer and the oxygen of lasting bubbling air carry out the ferrocene-based polymer reduction reaction.
Guarantee the sealing of gas in the whole testing process; The coupling of interferometer adopts end face butt joint coupling, and interferometer is divided into flashlight and interference light with light in the ratio of 1: 1 light intensity, transmits in signal arm and reference arm respectively.