CN207675632U - Gas-detecting device based on hollow core optical waveguide - Google Patents
Gas-detecting device based on hollow core optical waveguide Download PDFInfo
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Abstract
The utility model is related to a kind of gas-detecting devices, more particularly to a kind of gas-detecting device based on hollow core optical waveguide, the device includes internal hollow core optical waveguide, detecting laser, heat source laser, optical filter, detector, beam splitter and photo-coupler filled with tested gas, the output wavelength of the heat source laser is overlapped with the absorption spectral peak of tested gas, and photo-coupler is used for heat source laser coupled into optical waveguide；Ensure that the two beams detection divided beams separated by beam splitter synchronization passes sequentially through hollow core optical waveguide in different time and reaches detector simultaneously when detection and interferes superposition, the heat source laser light path of continuous illumination to change light beam by waveguide during a branch of light splitting is by optical waveguide is controlled simultaneously, and do not shine when the light splitting of another beam passes through optical waveguide, tested gas concentration is reflected with the difference between the superposed signal received before and after detector.
Description
Technical field
The utility model is related to a kind of gas-detecting devices, and in particular to a kind of gas detection dress based on hollow core optical waveguide
It sets.
Background technology
TDLAS (tunable diode laser absorption spectroscopy) technology is the wavelength tuning characteristic using diode laser,
The absorption spectrum for obtaining chosen under test gas characteristic absorption line, to carry out qualitative or quantitative analysis to polluted gas.
The trace gas detection method of TDLAS principles has many advantages, such as that response is fast, selectivity is strong, Ling Dugao, environmental protection, security protection,
The fields such as biochemistry are widely applied.But absorption light path (the generally longer and need due to the sensitivity of measurement dependent on gas
Open light path), it needs more accurate adjustment and there are larger dead volumes；And it is limited to the measuring principle of TDLAS, light path
In cannot have interference to prevent measurement baseline from shaking.These features all limit the application based on TDLAS principle detection methods.Light
Thermal acoustic spectroscopic methodology can evade the drawbacks described above based on TDLAS measurement methods, but generally require the difficult photoacoustic cell of structure manufacture
The expensive sound sensing device with value.
In the prior art, one entitled " gas sensor and the method for detecting the variation of hydrogen fluoride gas concentration "
Chinese invention patent application (application publication number CN106908389A) disclose a kind of gas sensor and for detecting fluorine
Change the method for hydrogen gas concentration variation, the program is provided with F-P resonant cavity in light path, and hydrogen fluoride gas is charged therein,
The pump light that the wavelength that spectral peak overlaps is absorbed with hydrogen fluoride is injected into the resonant cavity, the pump light meeting and fluorine in resonant process
Changing hydrogen and generating photo-thermal phenomenon causes gas refracting index in resonant cavity to change to influence absolute light path, at this moment allows pulse
Detection light injects the resonant cavity, is then reflect off from the resonant cavity, passes through 1：1 coupler, wherein 99% detection light weight
Newly return to annular light path lay equal stress on newly enter resonant cavity, in addition 1% light be received by a detector, such pulse detection light is in annular chamber
Interior multiple cycle does not stop to decay, simultaneously because the variation of light path also results in the loop attenuation of detection optical signal in resonant cavity
(light path is longer, and loss is bigger), therefore detector received signal is exactly a kind of pulse signal for declining and swinging, and passes through measure annular chamber
Ring-down time be obtained with the concentration of hydrogen fluoride.The scheme of this application can utilize TDLAS principles to change in resonant cavity
Light path, and the concentration of gas is measured using the ring-down time that swings signal is declined, but the program needs to be detected light and is converted to arteries and veins
Signal optical mode is rushed, while also to use accurate F-P resonant cavity and high-responsivity and high-precision detector, increases and sets
Count difficulty and manufacturing cost.
Currently, there is an urgent need for a kind of defect for not only having overcome traditional TDLAS measurement methods existing, but also design is simple, manufacturing cost is low
The device of honest and clean gas detection.
Utility model content
The purpose of this utility model be to provide it is a kind of based on the gas-detecting device of hollow core optical waveguide to solve current optical fiber
The complicated problem of gas-detecting device.
The utility model is in order to solve the above technical problems, provide scheme one：One kind of the utility model is based on hollow light wave
The gas-detecting device led, the device include the hollow core optical waveguide (4) filled with tested gas for inside, detecting laser (1),
Heat source pulse laser (2) and detector (6), the hollow core optical waveguide (4) include for into optical signals first port (M) and
Second port (N), the pulse laser of the heat source pulse laser (2) output are used to that photo-thermal effect, the heat to occur with tested gas
Source pulse laser (2) is of coupled connections with the hollow core optical waveguide (4)；
The device further includes the beam splitter (3) being connect with detecting laser (1) optical fiber, and the beam splitter (3) is by the detection
The detection light that laser (1) is sent out is divided into the first detection light splitting and the second detection is divided；The first detection light splitting passes through the first light
Road (I) reaches the first port (M) of the hollow core optical waveguide (4) and is projected from its second port (N), then passes through the second light path (II)
Reach the detector；The second detection light splitting reaches the second port (N) of the hollow core optical waveguide (4) by third light path (III)
And projected from its first port (M), then the detector is reached by the 4th light path (IV)；First light path (I) and second light
The length summation on road (II) and the third light path (III) are identical as the length summation of the 4th light path (IV), first light path (I)
It is different from the length of the third light path (III)；The detector (6) receives the first detection light splitting and the second detection spectral interference is folded
Optical signal after adding.
The length of the length of first light path and third light path is set as different value by this programme, makes two beams of this while outgoing
Detection divided beams one in front and one in back passes sequentially through the hollow core optical waveguide, when control heat source pulse laser (3) is sent out at same time point
Any divided beams in the two detection light splitting gone out persistently exports heat source light in the process by hollow core optical waveguide (4), and at another point
Light by the optical waveguide (4) during stop output heat source light when, when heat source laser does not export heat source light, by adjusting
The length of second light path and the 4th light path enables two divided beams to reach the detector simultaneously, at this time since two beam divided beams are complete
It is exactly the same, so stable interference superposed signal can be formed on the detector；If heat source laser (3) is emitted simultaneously at this
Two beams detect a branch of detection divided beams in divided beams by persistently exporting heat source light during hollow core optical waveguide, and in another beam
Stop output heat source light during divided beams is detected by the optical waveguide, then when two beam divided beams reach detector, by
In the photo-thermal effect of gas, gas molecule and exciting light interaction, interior energy increase, and refractive index or light path change, and lead to hollow
Optical waveguide corresponding light path in the case of being connected with heat source light from obstructed heat source light is different, and such two beams beam divided beams reaches detection
The time of device just has difference, interference superposed signal just to will appear difference, which can reflect the concentration of tested gas
Information.Entire structure of the detecting device is simple, and hardware requirement is relatively low, while also having higher measurement accuracy.
Scheme two：On the basis of scheme one, which further includes the first optical circulator (5-1) and the second optical circulator
(5-2), first optical circulator (5-1) and the second optical circulator (5-2) respectively include first port (D), second port (E) and
Third port (F)；The respective first port of two optical circulators (D) can will be from the optical transport that the port inputs to respective optical circulator
Second port (E), the second ports (E) of two optical circulators can will be from the optical transport that the port inputs to respective optical circulator
Third port (F)；
First optical circulator (5-1) is placed in first light path, and first port (D) connects with the first light path optical fiber
It connects, second port (E) is connect with first port (M) optical fiber of the hollow core optical waveguide (4), third port (F) and the detection
Device (6) optical fiber connects；Second optical circulator (5-2) is placed in second light path, first port (D) and the second light path light
Fibre connection, second port (E) connect with second port (N) optical fiber of the hollow core optical waveguide (4), third port (F) and this
Detector (6) optical fiber connects.
This programme specifically used two optical circulators carry out corresponding light path connection, can be reduced using optical circulator
The structure of light path is simplified in the use of optical fiber, this is a kind of optimal light path connection type, if optical coupling can also be used certainly
The light path that other optical connectors such as device carry out implementation six with optical fiber cooperation connects.
Scheme three：On the basis of scheme two, along detection divided beams direction of advance, first light path (I) is with first ring of light
Row device (5-1) is that boundary is divided into the 5th light path (V) and the 6th light path (VI), and the third light path (III) is with the second optical circulator (5-2)
It is divided into the 7th light path (VII) and the 8th light path (VIII) for boundary, six light path (VI) is different from the 8th light path (VIII) length,
The length of 5th light path (V) and the length summation and the 7th light path (VII) and the 4th light path (IV) of second light path (II)
It is identical to spend summation.
This programme two divided beams commonly through light path (the 6th light path, hollow core optical waveguide and the 8th light path) on, pass through
The optical path length that a certain divided beams gets ahead is added, to form time difference of two divided beams by the hollow core optical waveguide, simultaneously because
This light path is that two divided beams are required for by therefore not needing other light paths to compensate the above-mentioned optical path length deliberately added
Degree.
Scheme four：On the basis of scheme three, the 5th light path (V) is identical as the 7th light path (VII) length.
This programme gives a kind of simple plan of establishment of each light path, i.e. the second light path is identical as the 4th optical path length, the
Five light paths are identical as the 7th optical path length, only set the 6th light path and the 8th light path to different length, facilitate present apparatus light
The arrangement on road reduces light path installation and debugging difficulty, further simplifies light channel structure.
Scheme five：On the basis of scheme one to four, one group is provided on the wave guide wall of the hollow core optical waveguide (4) for being tested
The microchannel that gas enters.
This programme increases by opening up microchannel on the wave guide wall of hollow core optical waveguide and is tested the speed that gas enters optical waveguide
Degree, improves the detection efficiency of this gas-detecting device.
Scheme six：On the basis of scheme five, which further includes photo-coupler (7), which is located at the sky
At the port of core optical waveguide (4), the pulse laser for sending out the heat source pulse laser is coupled into the hollow core optical waveguide
(4)。
Photo-coupler is placed in the port position of hollow core optical waveguide by this programme, and heat source laser is enable accurately to provide
Change the environment inside hollow core optical waveguide in time, and then can accurately change light path of the divided beams by hollow core optical waveguide,
Improve final testing result.
Scheme seven：On the basis of scheme six, which further includes for filtering out the remnants by the hollow core optical waveguide (4)
The optical filter (8) of pulse laser.
The laser pulse that heat source pulse laser is sent out be exactly in order to tested gas occur photo-thermal effect, this programme in order to
Influence of the remaining laser pulse to testing result is avoided, between exit end and detector of the laser pulse from hollow core optical waveguide
Light path on be provided with the optical filter for being exclusively used in filtering out the laser pulse wavelength, and then improve final detection result precision and
Accuracy.
Scheme eight：On the basis of scheme seven, 180 ° of light phase changers are additionally provided in the second light path or the 4th light path
(9)。
Due to, when not exporting heat source light, final detector receives in scheme before two identical divided beams by
It is reached in simultaneously, therefore two beam interferences are superimposed, forms the signal for being more than each light splitting beam brightness, use such signal as base
Standard is detected, and reduces detector sensitivity and acquisition precision, and this programme is set in the light path of a branch of detection divided beams
180 ° of light phase changers are equipped with, so that the phase of two divided beams is differed 180 °, frosting phenomenon has occurred after two light splitting beam interferometer superpositions,
Increase detector sensitivity, and then increases the precision of detection.
Scheme nine：On the basis of scheme eight, the splitting ratio of the beam splitter (3) is 50：50.
When the splitting ratio of beam splitter is 50：50, complete extinction effect is can be only achieved, this is a kind of optimal scheme, certainly
It is that can also carry out gas detection with the beam splitter of other splitting ratios, only effect is not good enough.
Scheme ten：On the basis of scheme nine, which is connected as single mode optical fiber connection, which is InGaAs
Detector.
This programme using single mode optical fiber carry out optical fiber connection, ensure that divided beams in a fiber by light path precision, into
And improve final accuracy of detection.
Description of the drawings
Fig. 1 is the structural schematic diagram of the utility model gas-detecting device embodiment one；
Fig. 2 is the structural schematic diagram of the utility model gas-detecting device embodiment two；
Fig. 3 is the structural schematic diagram of the utility model gas-detecting device embodiment three；
Fig. 4 is a kind of structural schematic diagram of hollow core optical waveguide of the utility model；
Wherein, 1 is detecting laser, and 2 be heat source laser, and 3 be beam splitter, and 4 be hollow core optical waveguide, and 5-1 is the first light
Circulator, 5-2 are the second optical circulator, and 6 be detector, and 7 be photo-coupler, and 8 be optical filter, and 9 be 180 ° of light phase changers, 10
It is acquisition control unit for 10Km single mode optical fibers, 11,12 be host computer.
Specific implementation mode
With reference to the accompanying drawings of the specification, several specific embodiments of the gas-detecting device of the utility model are provided, and
It is described in detail in conjunction with attached drawing：
If Fig. 1 is a kind of the first embodiment of gas-detecting device based on hollow core optical waveguide of the utility model,
Tested gas (such as CH is charged including being used for inside4) hollow core optical waveguide (4), (such as output wavelength is detecting laser (1)
The infrared laser of 1550nm), heat source laser (2), the optical filter being used for (8), detector (6) (such as InGaAs detectors)
With photo-coupler (7), which includes being somebody's turn to do for the first port (M) and second port (N) into optical signals
The output wavelength of heat source laser (2) is overlapped with the absorption spectral peak of tested gas (is tested gas as CH4When its wavelength be
1653.72nm), which is used for the output heat source optical coupling of the heat source laser (2) into the hollow core optical waveguide
(4) in, which is used to filter out heat source laser (2) residual heat by the hollow core optical waveguide (4)
Source light.
The device further includes the beam splitter (3) being connect with detecting laser (1) optical fiber, the first optical circulator (5-1) and
Second optical circulator (5-2), the beam splitter (3) include input terminal (A), the first output end (B) and second output terminal (C), this point
Beam device (3) by input into detection light be divided into while two beams that are emitted detect divided beams, wherein a branch of detection divided beams passes through the
One light path (I) and the second light path (II) reach the detector (6), and another beam detection divided beams is by third light path (III) and the
Four light paths (IV) reach the detector (6).
First optical circulator (5-1) and the second optical circulator (5-2) include respectively first port (D), second port (E)
With third port (F)；The respective first port of two optical circulators (D) can will be from the optical transport that the port inputs to respective ring of light row
The second port (E) of device, the second ports (E) of two optical circulators can will be from the optical transports that the port inputs to respective optical circulator
Third port (F)；The first port (D) of first optical circulator (5-1) and the first output end (B) light of the beam splitter (3)
Fibre connection, the second port (E) of first optical circulator (5-1) connect with first port (M) optical fiber of the hollow core optical waveguide (4)
It connects, the third port (F) of first optical circulator (5-1) is connect with detector (6) optical fiber, second optical circulator (5-2)
First port (D) connect with second output terminal (C) optical fiber of the beam splitter (3), the second end of second optical circulator (5-2)
Mouth (E) is connect with second port (N) optical fiber of the hollow core optical waveguide (4), the third port (F) of second optical circulator (5-2)
It is connect with detector (6) optical fiber.
Along detection divided beams direction of advance, which is the first output end (B) of the beam splitter (3) to the sky
The optical fiber connecting path of the first port (M) of core optical waveguide (4), second light path (II) are the second of the hollow core optical waveguide (4)
To the optical fiber connecting path of detector (6), which is the second output terminal (C) of the beam splitter (3) for port (N)
To the optical fiber connecting path of the second port (N) of the hollow core optical waveguide (4), the 4th light path (IV) is the hollow core optical waveguide (4)
First port (M) to the optical fiber connecting path of detector (6), first light path (I) and the length of second light path (II) are total
With, first light path (I) and the third light path identical as the length summation of the 4th light path (IV) as the third light path (III)
(III) length is different.
The heat source laser (3) be pulse laser, pulse output frequencies ensure the heat source laser (3) this simultaneously
A branch of detection divided beams in the two beams detection divided beams of outgoing persistently exports heat source light in the process by hollow core optical waveguide (4),
And stop output heat source light during another beam detects divided beams by optical waveguide (4)；The detector (6) receives two beams
Optical signal after detection light splitting beam interferometer superposition.
In above-described embodiment one, the length of the length of the first light path and third light path is set as different value, keeps this same
When be emitted two beams detection divided beams one in front and one in back pass sequentially through the hollow core optical waveguide, when heat source laser does not export heat source light
When, by adjusting the length of the second light path and the 4th light path, so that two divided beams is reached the detector simultaneously, at this time due to two
Beam divided beams is identical, so stable interference superposed signal can be formed on the detector；If heat source laser (3) is at this
A branch of detection divided beams in the two beams detection divided beams of outgoing simultaneously persistently exports heat source light in the process by hollow core optical waveguide,
And stop output heat source light during another beam detects divided beams by the optical waveguide, then being visited when two beam divided beams reach
When surveying device, due to the photo-thermal effect of gas, gas molecule and exciting light interaction, interior energy increase, and refractive index or light path change,
Cause hollow core optical waveguide corresponding light path in the case of being connected with heat source light from obstructed heat source light different, such two beams beam divided beams
The time for reaching detector just has difference, interference superposed signal just to will appear difference, which can reflect tested gas
The concentration information of body.
If Fig. 2 is a kind of second of embodiment of gas-detecting device based on hollow core optical waveguide of the utility model,
The photo-coupler (7) that differs only in of itself and embodiment one is located at the port of the hollow core optical waveguide (4), enables in this way
The heat source light that heat source laser is sent out quickly enters in optical waveguide, and then the refractive index for rapidly changing the gas in optical waveguide improves
Final testing result.
If Fig. 3 is a kind of the third embodiment of gas-detecting device based on hollow core optical waveguide of the utility model,
Difference lies in the embodiment, along detection divided beams direction of advance, by the first light path (I) with the first light with embodiment two for it
Circulator (5-1) is that boundary is divided into the 5th light path (V) and the 6th light path (VI), by third light path (III) with the second optical circulator (5-
2) it is that boundary is divided into the 7th light path (VII) and the 8th light path (VIII), and is connected with 10Km in the 6th light path (VI) and (can also be
The length of setting, while can also be placed in the 8th light path) single mode optical fiber, the 5th light path (V) and the 7th light path (VII) length
Spend identical, the second light path (II) is identical as the 4th light path (IV) length.
The present embodiment two divided beams commonly through light path (the 6th light path, hollow core optical waveguide and the 8th light path) on, lead to
It crosses and adds the optical path length that a certain divided beams gets ahead, to form time difference of two divided beams by the hollow core optical waveguide, while by
It is that two divided beams are required for by therefore not needing other light paths to compensate the above-mentioned optical path length deliberately added in this light path
Degree.For other light paths, it is only necessary to the second light path is identical as the 4th optical path length, and the 5th light path is identical as the 7th optical path length,
Energy fast and easy completes the arrangement of this light path, reduces light path installation and debugging difficulty, has further simplified light channel structure.
It is used for making dry two divided beams to reach detection equipped with 180 ° of light phase changer also in the 4th light path in embodiment three
In interference cancellation position when device, to increase the sensitivity of detection.
Additional embodiment three identifies acquisition control unit (11) and host computer (12), acquisition control unit and detector
Sampling connection, for acquiring detector signal, host computer is connect with acquisition control unit controlling of sampling, is used for human-computer interaction.It should
Acquisition control unit is also responsible for sending out control signal (such as sawtooth wave, triangular wave, the side of the control heat source laser of certain frequency
Wave), certain control signal may also set up special cell output.
Due to, when not exporting heat source light, final detector receives in scheme before two identical divided beams by
It is reached in simultaneously, therefore two beam interferences are superimposed, forms the signal for being more than each light splitting beam brightness, use such signal as base
Standard is detected, and reduces the acquisition precision of detector, and this programme is provided with 180 ° in the light path of a branch of detection divided beams
Light phase changer makes the phase of two divided beams differ 180 °, frosting phenomenon has occurred after two light splitting beam interferometer superpositions, increases detection
The sensitivity of device, and then increase the precision of detection.
The measuring principle of above-described embodiment is：Above-described embodiment hollow core optical waveguide couples company with heat source pulse laser
It connects, when the heat source pulse laser exports pulse laser to hollow core optical waveguide, which starts, if ensured wherein
One light beam by hollow core optical waveguide during into hollow core optical waveguide input heat source laser pulse, pass through hollow in another light beam
Not heat outputting source laser pulse during optical waveguide, since frequency is identical, phase difference is identical, direction of vibration is identical, vibration width
It is worth identical two light beam in different moments by the hollow core optical waveguide, and reaches detector in synchronization later；When detection, together
When the identical light of two beams that is emitted, wherein it is a branch of when passing through hollow core optical waveguide since photo-thermal effect does not occur for tested gas
(no pulse laser is inputted into optical waveguide) normally reaches detector, and another beam when passing through hollow core optical waveguide due to tested gas hair
Given birth to photo-thermal effect (thering is pulse laser to input into optical waveguide), the light path of the light beam caused to change, because be unable to and its
The light beam of outgoing reaches detector simultaneously simultaneously, allows for the detection signal that detector receives in this way and is sent out relative to reference signal
Given birth to variation, and the variation of light path decides that the size of the signal intensity is strong and weak in optical waveguide, and the variation of light path then completely by
The strong and weak of photo-thermal effect determines that the strong and weak of photo-thermal effect is then determined by tested gas concentration, therefore final detection signal and benchmark
The difference of signal can reflect the concentration information of tested gas.
Since detector is very sensitive for the induction of light intensity variation in certain light intensity, when light intensity is too strong, Jiu Huiying
Detector sensitivity is rung, it can be by ensureing that two light beam vibration amplitudes are identical and any light beam arrives in two light beams in aforesaid operations
180 ° of light phase changers are set on up to the light path of detector, are occurred when making two light beams being emitted simultaneously while reaching detector complete
Delustring realizes that the reference signal that sets as zero, can increase detector sensitivity using extinction signals as reference signal, in turn
Increase the precision of testing result.
In above-described embodiment, photo-coupler (7) include three ports, be respectively first port (G), second port (H) and
Third port (I), light between its first port (G) and second port (H) can bidirectional conduction, and cannot be from its third port
(I) be emitted, and from its third port (I) input into optical signal can only be from second port (H) one-way conduction.
In above-described embodiment, it is only necessary to ensure that being tested gas is evenly distributed in hollow core optical waveguide i.e. during test
Can, to increase the speed for being tested gas and entering hollow core optical waveguide, one group of microchannel can be provided on hollow core optical waveguide wall, it should
Microchannel is that femto-second laser punches, and when gas molecule reaches center, that is, traveling wave channel of hollow core optical waveguide, and is passed through
The laser photon of hollow core optical waveguide interacts.Tested gas, which can be greatly speeded up, using this hollow core optical waveguide enters optical waveguide
Speed, improve detection efficiency.
Optical circulator is used in above-described embodiment to realize the connection of light path, the benefit using optical circulator is to reduce light
Fine use further simplifies light path connection structure, but equally optical fiber and photo-coupler, light connects device etc. can also be used normal
Fiber optic components are seen to complete building for light path in embodiment.
Specific embodiment is presented above, but the utility model is not limited to described embodiment.This practicality
Novel basic ideas are above-mentioned basic scheme, in the case where not departing from the principles of the present invention and spirit to embodiment party
The change, modification, replacement and modification that formula carries out are still fallen in the scope of protection of the utility model.
Claims (10)
1. a kind of gas-detecting device based on hollow core optical waveguide, it is characterised in that：The device is tested including being charged for inside
The hollow core optical waveguide (4) of gas, detecting laser (1), heat source pulse laser (2) and detector (6), the hollow core optical waveguide
(4) include for the first port (M) and second port (N) into optical signals, the arteries and veins of heat source pulse laser (2) output
Impulse light is used to that photo-thermal effect to occur with tested gas, and the heat source pulse laser (2) couples with the hollow core optical waveguide (4)
Connection；
The device further includes the beam splitter (3) being connect with the detecting laser (1) optical fiber, and the beam splitter (3) is by the spy
It surveys the detection light that laser (1) is sent out and is divided into the first detection light splitting and the second detection light splitting；The first detection light splitting passes through the
One light path (I) reaches the first port (M) of the hollow core optical waveguide (4) and is projected from its second port (N), then passes through the second light
Road (II) reaches the detector；The second detection light splitting reaches the hollow core optical waveguide (4) by third light path (III)
Second port (N) is simultaneously projected from its first port (M), then reaches the detector by the 4th light path (IV)；First light
The length on road (I) and the length summation and the third light path (III) and the 4th light path (IV) of second light path (II)
Summation is identical, and first light path (I) is different from the length of third light path (III)；The detector (6) receives described the
Optical signal after one detection light splitting and the second detection spectral interference superposition.
2. the gas-detecting device according to claim 1 based on hollow core optical waveguide, it is characterised in that：The device further includes
First optical circulator (5-1) and the second optical circulator (5-2), first optical circulator (5-1) and the second optical circulator (5-2)
Include respectively first port (D), second port (E) and third port (F)；The respective first port of two optical circulators (D) can incite somebody to action
From the optical transport that the port inputs to the second port (E) of respective optical circulator, the second ports (E) of two optical circulators can will be from
The port input optical transport to respective optical circulator third port (F)；
First optical circulator (5-1) is placed in first light path, and first port (D) connects with the first light path optical fiber
Connect, second port (E) is connect with first port (M) optical fiber of the hollow core optical waveguide (4), third port (F) with it is described
Detector (6) optical fiber connects；Second optical circulator (5-2) is placed in second light path, first port (D) with it is described
Second light path optical fiber connects, and second port (E) is connect with second port (N) optical fiber of the hollow core optical waveguide (4), third
Port (F) is connect with the detector (6) optical fiber.
3. the gas-detecting device according to claim 2 based on hollow core optical waveguide, it is characterised in that：Before detection light splitting
Into direction, first light path (I) is that boundary is divided into the 5th light path (V) and the 6th light path (VI), institute with the first optical circulator (5-1)
It is that boundary is divided into the 7th light path (VII) and the 8th light path (VIII) that third light path (III), which is stated, with the second optical circulator (5-2), described
Six light paths (VI) are different from the 8th light path (VIII) length, the length of the 5th light path (V) and second light path (II)
It spends summation and the 7th light path (VII) is identical as the length summation of the 4th light path (IV).
4. the gas-detecting device according to claim 3 based on hollow core optical waveguide, it is characterised in that：5th light path
(V) identical as the 7th light path (VII) length.
5. according to any gas-detecting devices based on hollow core optical waveguide of claim 1-4, it is characterised in that：The sky
One group of microchannel for being tested gas entrance is provided on the wave guide wall of core optical waveguide (4).
6. the gas-detecting device according to claim 5 based on hollow core optical waveguide, it is characterised in that：The device further includes
Photo-coupler (7), the photo-coupler (7) are located at the port of the hollow core optical waveguide (4), for swashing the heat source pulse
The pulse laser that light device is sent out is coupled into the hollow core optical waveguide (4).
7. the gas-detecting device according to claim 6 based on hollow core optical waveguide, it is characterised in that：The device further includes
For filtering out the optical filter (8) by the residual pulse laser of the hollow core optical waveguide (4).
8. the gas-detecting device according to claim 7 based on hollow core optical waveguide, it is characterised in that：In second light
180 ° of light phase changers (9) are additionally provided in road or the 4th light path.
9. the gas-detecting device according to claim 8 based on hollow core optical waveguide, it is characterised in that：The beam splitter
(3) splitting ratio is 50：50.
10. the gas-detecting device according to claim 9 based on hollow core optical waveguide, it is characterised in that：The optical fiber connects
It is connected in single mode optical fiber connection, the detector (6) is InGaAs detectors.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110501781A (en) * | 2019-08-30 | 2019-11-26 | 北京智芯微电子科技有限公司 | The forming method of waveguide and SF6 gas passive sensor comprising the waveguide |
| CN112924386A (en) * | 2019-12-06 | 2021-06-08 | 香港理工大学深圳研究院 | Fluid concentration detection method and system |
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2017
- 2017-12-30 CN CN201721906988.3U patent/CN207675632U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110501781A (en) * | 2019-08-30 | 2019-11-26 | 北京智芯微电子科技有限公司 | The forming method of waveguide and SF6 gas passive sensor comprising the waveguide |
| CN112924386A (en) * | 2019-12-06 | 2021-06-08 | 香港理工大学深圳研究院 | Fluid concentration detection method and system |
| CN112924386B (en) * | 2019-12-06 | 2024-05-07 | 香港理工大学深圳研究院 | Fluid concentration detection method and system |
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