CN107328404A - The super large Sagnac interference optical fiber tops of effective fiber length N multiplications - Google Patents
The super large Sagnac interference optical fiber tops of effective fiber length N multiplications Download PDFInfo
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- CN107328404A CN107328404A CN201710631991.7A CN201710631991A CN107328404A CN 107328404 A CN107328404 A CN 107328404A CN 201710631991 A CN201710631991 A CN 201710631991A CN 107328404 A CN107328404 A CN 107328404A
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- optical fiber
- image intensifer
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- photoswitch
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
- G01C19/58—Turn-sensitive devices without moving masses
- G01C19/64—Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams
- G01C19/72—Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams with counter-rotating light beams in a passive ring, e.g. fibre laser gyrometers
- G01C19/721—Details
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- Optics & Photonics (AREA)
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- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
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Abstract
The present invention relates to a kind of super large Sagnac interference optical fiber tops of effective fiber length N multiplications, including Y shape branch-waveguide modulator, fiber optic sensing coil, fiber coupler, photoelectric detector, two optical fiber splitters, image intensifer and photoswitch, the break-make of photoswitch and the working condition of image intensifer realize that fiber lengths N doubles.Photoswitch, fiber coupler and Y shape branch-waveguide modulator are sequentially connected in series, photoelectric detector connects fiber coupler, two inputs of optical fiber splitter one are connected with Y shape branch-waveguide modulator, another input is connected with image intensifer, circulating loop is constituted, an output end of two optical fiber splitters is connected with fiber optic sensing coil two ends.Compared with prior art, the present invention can make the effective length of fiber optic sensing coil increase N times, and can export the Sagnac signals of 1~N of effective fiber length multiplications, be conducive to nonreciprocal error phase shift to suppress.
Description
Technical field
The present invention relates to a kind of interferometric fiber optic gyroscope, the super large doubled more particularly, to a kind of effective fiber length N
Sagnac interference optical fiber tops.
Background technology
Interference optical fiber top is the inertial navigation device based on Sagnac fiber optic sensing coils and integrated optical device
Part, is that inertia system perceives carrier certainly for independently measuring rotary motion (angular velocity of rotation) of the carrier relative to inertial space
Exact position and direction of body etc. have key effect.Optical gyroscope is the angular-rate sensor based on Sagnac effects,
Sagnac effects are：When optical loop coil rotates, clockwise with passing through counterclockwise between the two-beam of same loop transfer
Produce phase difference.Interference optical fiber top (IFOG) be exactly it is clockwise with counterclockwise by between fiber optic sensing coil transmission light
Phase signal is converted to output light intensity signal by interference, electric signal is converted to through photoelectric detector, by gyro processing of circuit
Export the angular velocity of rotation of carrier.Therefore there is no moving component in optical fibre gyro, and because the loss of optical fiber is extremely low, length is reachable
To kilometer level, precision can reach 0.001o/h grades.And optical fibre gyro have shock resistance, the long-life, precision height, price, size,
There is obvious advantage in terms of weight, be adapted to the advantage of large-scale production, in industry with having expanded many newer use in Military Application
On the way, as one of inertia device with the fastest developing speed at present.
The main technical performance index of interference optical fiber top has constant multiplier and its stability and symmetry, angle random
Migration and bias instaility.The main cause of influence scale factor stability and symmetry has light source average central wavelength and sensing
The stability of loop length, and Y shape branch-waveguide modulator and signal processing circuit the linearity.Angle random walk is letter
Make an uproar than related parameter, be the measurement of gyro minimum detectable sensitivity, have with Equalization Design and noise suppressed and filtering technique
Close.Zero inclined stability of gyro may be considered the credible detection sensitivity of gyro, and the zero offset error of gyro is essentially from polarization-maintaining
Fiber optic sensing coil, including polarization interference, Faraday effect, caused by time-varying environment temperature and stress (vibration and sound wave) it is non-mutually
Easy phase shift.Interference optical fiber top is made up of sensing optical gauge outfit and modulation-demodulation circuit two parts, traditional sensing optical table
Head is made up of integrated Y shape branch-waveguide modulator and fiber optic sensing coil again.The precision of optical fibre gyro is mainly by sensing optical
What gauge outfit was determined, be also the main error source of gyro.
What the main maximum by sensitivity and zero offset error of the precision of interference optical fiber top was determined.Sensitivity is top
Minimum detectable signal size in spiral shell system, and minimum detection signal be Sagnac signals and zero offset error and.The opposing party
Face, the corresponding minimum detectable phase difference of sensitivity of photoelectric detector is in differential of the arc measurement level, Sagnac phase shifts and sensor fibre
Length, angular speed are directly proportional, so, increase sensor coil fiber lengths are that raising interference optical fiber top sensitivity and precision are straight
Connect effective method.But, the increase of sensor coil fiber lengths not only increases cost, volume, weight, wire winding difficult
Degree, can also increase the nonreciprocal errors such as polarization interference, Shuppe effects and vibrations, this can increase interference optical fiber top on the contrary
Bias instaility；Moreover, sensor fibre is longer, loss is bigger, and this can increase angle random trip of interference optical fiber top on the contrary
Walk, can not finally reach the purpose for improving Gyro Precision.
The content of the invention
It is an object of the present invention to overcome the above-mentioned drawbacks of the prior art and provide a kind of effective fiber length N
The super large Sagnac interferometer structure gyros of multiplication, with shorter actual fiber sensor coil length, pass through effective fiber length N
Multiplication produces the Sagnac phase shift signal of multiplication, and nonreciprocal error phase shift can maintain actual fiber coil size, solves to use
Super large sensing fiber coil increases the contradiction between Sagnac phase shifts and zero offset error.Research compensates belt damage with image intensifer
Consumption, solves the contradiction between increase Sagnac phase shifts and reduction angle random walk.
The purpose of the present invention can be achieved through the following technical solutions：
A kind of super large Sagnac interference optical fiber tops of effective fiber length N multiplications, including the modulation of Y shape branch-waveguide
Device, fiber optic sensing coil, light source, fiber coupler and photoelectric detector, in addition to photoswitch, two optical fiber splitters and light are put
Big device a, input of described two optical fiber splitters is connected with Y shape branch-waveguide modulator, and another input is put with light
Big device connects and composes circulating loop, and the output end of two optical fiber splitters is connected with the two ends of fiber optic sensing coil respectively, described
Two optical fiber splitters, image intensifer and fiber optic sensing coil formation optical loop, the photoswitch are connected to light source and optical fiber
Between coupler.
Photoswitch transition state synchronous with image intensifer, when photoswitch is in opening state, image intensifer is in
Attenuation state, when photoswitch is off, image intensifer is in gain-state, realizes that effective fiber length N doubles.
The service time of the photoswitch is equal to fiber optic sensing coil transmission time τ, and the turn-off time is (N-1) τ, and the cycle is
Nτ。
It is described to realize that effective fiber length N multiplications are specially：
Photoswitch is in opening state, and image intensifer is in attenuation state, and light source is adjusted through fiber coupler and y branch waveguide
Device processed exports light clockwise and light counterclockwise, and light clockwise and light counterclockwise are corresponded to respectively enters optical fiber through two optical fiber splitters
After sensor coil, return to two optical fiber splitters and be divided into two-way output, this light switch switchs to off-state, and image intensifer switchs to
Gain-state, wherein exporting all the way through 1 output of going in ring of Y shape branch-waveguide modulator formation, another road output is through image intensifer
Fiber optic sensing coil is returned to by two optical fiber splitters again afterwards, circulation forms the belt output of n times.
The photoelectric detector is detected successively obtains effective fiber length multiplication number by 1 to N gyro signal.
The image intensifer is erbium-doped fiber amplifier.
Compared with prior art, the present invention has advantages below：
(1) insert and go in ring back between CW and CCW directions of the present invention between y branch waveguide modulator and fiber optic sensing coil
Road, makes sensor coil effective fiber length increase N times, Sagnac phase shifts increase N times, and then gyro sensitivity is increased N times, can
Actual fiber sensor coil several kilometers long is multiplied to effective length and reaches tens to hundreds of kilometer.
(2) effective fiber length multiplication number is sequentially output by 1 to N gyro signal, can be obtained in different multiplicative processes
Nonreciprocal error phase shift information, the nonreciprocal error phase shift compensation in gyro signal that N is doubled is to actual fiber coil size.
(3) actual fiber winding volume and weight are several kilometers of sizes, can realize super large with several kilometers of coil winding techniques
Sagnac interferometers.
Brief description of the drawings
Fig. 1 is structural representation of the invention；
Fig. 2 is opened with the decay for disconnecting two states and image intensifer with amplifying two state synchronized timing diagrams for photoswitch,
Wherein, (a) is optical switch status timing diagram, and (b) is image intensifer state timing chart, and (c) is Output optical power state timing chart.
Embodiment
The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings.The present embodiment is with technical solution of the present invention
Premised on implemented, give detailed embodiment and specific operating process, but protection scope of the present invention is not limited to
Following embodiments.
As shown in figure 1, the present embodiment provides a kind of super large Sagnac interference-type optical fiber tops of effective fiber length N multiplications
Spiral shell, including Y shape branch-waveguide modulator 4, fiber optic sensing coil 8, light source 1, fiber coupler 3, photoelectric detector 9, photoswitch
2nd, two optical fiber splitters 5,6 and image intensifer 7, an input of two optical fiber splitters 5,6 are modulated with Y shape branch-waveguide
Device 4 is connected, and another input connects and composes circulating loop, the output end difference of two optical fiber splitters 5,6 with image intensifer 7
It is connected with the two ends of fiber optic sensing coil 8, two optical fiber splitters 5,6, image intensifers 7 form optics with fiber optic sensing coil 8
Loop, photoswitch 2 is connected between light source 1 and fiber coupler 3.
Photoswitch 2 and the synchronous transition state of image intensifer 7, when photoswitch 2 is in opening state, image intensifer 7 is in
Attenuation state, when photoswitch 2 is off, image intensifer 7 is in gain-state, realizes that effective fiber length N doubles.
The service time of photoswitch is equal to fiber optic sensing coil transmission time τ, and the turn-off time is (N-1) τ, and the cycle is N τ.Photoelectric Detection
Device 9 is detected successively obtains effective fiber length multiplication number by 1 to N gyro signal.In the present embodiment, image intensifer 7 is er-doped
Fiber amplifier.Fiber coupler 3 is 3dB fiber couplers.
As shown in Fig. 2 light source 1 is through the photoswitch 2 in opening state, fiber coupler 3 and y branch waveguide modulator 4
CW clockwise and CCW two-way counterclockwise output are exported, CW light enters fiber optic sensing coil 8 through optical fiber splitter 5, reaches optical fiber point
During the device 6 of road, photoswitch 2 switchs to disconnected state by logical, and image intensifer 7 switchs to gain-state by decay, and the output of optical fiber splitter 6 is divided into
Two-way, reaching photoelectric detector 9 through y branch waveguide modulator 4 and fiber coupler 3 all the way turns into 1 multiplication gyro signal output,
After another route image intensifer 7 amplification compensation trip loss, fiber optic sensing coil 8 is again introduced into by optical fiber splitter 5, light is reached
During fine shunt 6, photoswitch 2 keeps disconnected state, and image intensifer 7 keeps gain-state, and the output of optical fiber splitter 6 is divided into two-way,
Reaching photoelectric detector 9 through y branch waveguide modulator 4 and fiber coupler 3 all the way turns into 2 multiplication gyro signal outputs, another
It route after the amplification compensation trip loss of image intensifer 7, fiber optic sensing coil 8 is again introduced into by optical fiber splitter 5, optical fiber point is reached
During the device 6 of road, photoswitch 2 keeps disconnected state, and image intensifer 7 keeps gain-state, and the cycle repeats, until N τ moment, image intensifer 7
Switch to attenuation state, the two-way that optical fiber splitter 6 is exported reaches light through y branch waveguide modulator 4 and fiber coupler 3 all the way
Photodetector 9 turns into N multiplication gyro signal outputs, and it is approximately 0 that then image intensifer 7, which is decayed after about 60dB, on another road.Meanwhile, light is opened
Close 2 and switch to logical state, CW clockwise and CCW light counterclockwise are inputted again, the cycle repeats, again by time slot output 1,2 ..., N times
Increase gyro signal output.
The foregoing examples are merely illustrative of the technical concept and features of the invention, the protection model of this invention can not be limited with this
Enclose.It is every according to inventive idea：Inserted between CW and CCW directions between y branch waveguide modulator and fiber optic sensing coil
Circulating loop, realizes equivalent transformation or the modification of Sagnac phase shifts multiplication, should all be included within the scope of the present invention.
Claims (6)
1. a kind of super large Sagnac interference optical fiber tops of effective fiber length N multiplications, including Y shape branch-waveguide modulator
(4), fiber optic sensing coil (8), light source (1), fiber coupler (3) and photoelectric detector (9), it is characterised in that also including light
(2), two optical fiber splitters (5,6) and image intensifer (7) are switched, an input of described two optical fiber splitters (5,6) is equal
It is connected with Y shape branch-waveguide modulator (4), another input connects and composes circulating loop, two optical fiber with image intensifer (7)
Two ends of the output end of shunt (5,6) respectively with fiber optic sensing coil (8) are connected, described two optical fiber splitters (5,6), light
Amplifier (7) is connected to light source (1) and fiber coupler with fiber optic sensing coil (8) formation optical loop, the photoswitch (2)
(3) between.
2. the super large Sagnac interference optical fiber tops of effective fiber length N multiplications according to claim 1, its feature exists
In, the photoswitch (2) transition state synchronous with image intensifer (7), when photoswitch (2) is in opening state, image intensifer
(7) attenuation state is in, when photoswitch (2) is off, image intensifer (7) is in gain-state, realizes effective light
Fine length N multiplications.
3. the super large Sagnac interference optical fiber tops of effective fiber length N multiplications according to claim 2, its feature exists
In the service time of the photoswitch is equal to fiber optic sensing coil transmission time τ, and the turn-off time is (N-1) τ, and the cycle is N τ.
4. the super large Sagnac interference optical fiber tops of effective fiber length N multiplications according to claim 2, its feature exists
In described to realize that effective fiber length N multiplications are specially：
Photoswitch (2) is in opening state, and image intensifer (7) is in attenuation state, and light source (1) is through fiber coupler (3) and Y points
Branch waveguide modulator (4) exports light clockwise and light counterclockwise, and light clockwise and light counterclockwise are corresponded to through two optical fiber point respectively
Road device (5,6) enters after fiber optic sensing coil (8), returns to two optical fiber splitters (5,6) and is divided into two-way output, this light switch
(2) off-state is switched to, image intensifer (7) switchs to gain-state, wherein exporting all the way through Y shape branch-waveguide modulator formation 1
Secondary belt output, another road output returns to fiber optic sensing coil by two optical fiber splitters (5,6) again after image intensifer (7)
(8), circulation forms the belt output of n times.
5. the super large Sagnac interference optical fiber tops of effective fiber length N multiplications according to claim 4, its feature exists
In the photoelectric detector (9) is detected successively obtains effective fiber length multiplication number by 1 to N gyro signal.
6. the super large Sagnac interference optical fiber tops of effective fiber length N multiplications according to claim 1, its feature exists
In the image intensifer (7) is erbium-doped fiber amplifier.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710631991.7A CN107328404B (en) | 2017-07-28 | 2017-07-28 | Oversized Sagnac interference type fiber-optic gyroscope with N-multiplied effective fiber-optic length |
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| CN201710631991.7A CN107328404B (en) | 2017-07-28 | 2017-07-28 | Oversized Sagnac interference type fiber-optic gyroscope with N-multiplied effective fiber-optic length |
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| CN112781578A (en) * | 2020-12-25 | 2021-05-11 | 湖南航天机电设备与特种材料研究所 | Optical fiber gyroscope with scale factor self-adaptive control and method |
| CN115839711A (en) * | 2023-02-16 | 2023-03-24 | 中国船舶集团有限公司第七〇七研究所 | Optical fiber gyroscope |
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| CN103940415A (en) * | 2014-03-26 | 2014-07-23 | 同济大学 | Polarization-maintaining fiber sensing loop structure of fiber optic gyroscope |
| CN105352491A (en) * | 2015-11-16 | 2016-02-24 | 中国电子科技集团公司第四十九研究所 | Y-waveguide structure for fiber-optic gyroscope light path extension |
| CN105973222A (en) * | 2016-06-17 | 2016-09-28 | 同济大学 | Sagnac phase shifting multiplication structure of interferometric fiber-optic gyroscope |
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| US20040223160A1 (en) * | 2003-05-06 | 2004-11-11 | Chung-Jen Chen | Fiber optic gyroscope sensing loop doubler |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108007481A (en) * | 2017-12-07 | 2018-05-08 | 上海第二工业大学 | A kind of system and method that light sensing is carried out using optics nonreciprocal device |
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| CN112781578A (en) * | 2020-12-25 | 2021-05-11 | 湖南航天机电设备与特种材料研究所 | Optical fiber gyroscope with scale factor self-adaptive control and method |
| CN112781578B (en) * | 2020-12-25 | 2022-07-15 | 湖南航天机电设备与特种材料研究所 | Optical fiber gyroscope with scale factor self-adaptive control and method |
| CN115839711A (en) * | 2023-02-16 | 2023-03-24 | 中国船舶集团有限公司第七〇七研究所 | Optical fiber gyroscope |
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