阅读说明：本技术 容忍模耦合存在基于双端偏振态检测的光纤陀螺新结构 (There is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling ) 是由 吴重庆 于 2019-07-16 设计创作，主要内容包括：本发明涉及光纤传感技术领域,尤其是容忍模耦合存在基于双端偏振态检测的光纤陀螺新结构,包括光源,光源的输出端通过光纤与偏振控制器的输入端相连,偏振控制器的输出端通过光纤连接在环行器的第一端口上,环行器的第二端口与光耦合器和光纤环构成的萨格纳克干涉仪的输入端相连；环行器的第三端口与第二光纤分束器PBS2相连；萨格纳克干涉仪的输出端与第一光纤分束器PBS1相连；两个偏振分束器的输出端分别与带有光探测器的数采卡相连；数采卡通过信号线与微机电性相连。本发明可以实现在容忍光纤存在模耦合的条件下,通过检测两个偏振分束器的输出信号,计算出光纤陀螺的角速度,可以使光纤陀螺的精度进一步提高、减小零点漂移。(The present invention relates to technical field of optical fiber sensing, there is the optical fibre gyro new construction detected based on both-end polarization state in especially tolerance mode coupling, including light source, the output end of light source is connected by optical fiber with the input terminal of Polarization Controller, the output end of Polarization Controller is connected in the first port of circulator by optical fiber, and the second port of circulator is connected with the input terminal of photo-coupler and the sagnac interferometer of fiber optic loop composition；The third port of circulator is connected with the second fiber optic splitter PBS2；The output end of sagnac interferometer is connected with the first fiber optic splitter PBS1；The output end of two polarization beam apparatus adopts card with the number with optical detector respectively and is connected；Number adopts card and is electrical connected by signal wire and microcomputer.The present invention may be implemented, by detecting the output signal of two polarization beam apparatus, to calculate the angular speed of optical fibre gyro there are under conditions of mode coupling in tolerance optical fiber, the precision of optical fibre gyro can be made to further increase, reduce null offset.)

1. tolerating the existing optical fibre gyro new construction based on the detection of both-end polarization state of mode coupling, which is characterized in that including light source (1), sagnac interferometer (4), the first optical fiber of Polarization Controller (2), circulator (3), photo-coupler and fiber optic loop composition Polarization beam apparatus PBS1 (5), the second fibre optic polarizing beam splitter PBS2 (6), the number with optical detector adopt card (7), microcomputer (8)；

The output end of the light source (1) is connected by optical fiber with the input terminal of Polarization Controller (2), the Polarization Controller (2) Output end be connected with the first port (10) of circulator (3)；

The sagnac interferometer (4) that the second port (11) of the circulator (3) and the photo-coupler and fiber optic loop are constituted Input terminal be connected；The input terminal phase of the output end of the sagnac interferometer (4) and the first fiber optic splitter PBS1 (5) Even, two output ends of the first fiber optic splitter PBS1 (5) adopt adopting for card (8) by optical fiber and the number with optical detector Collect end to be connected；

The third port (12) of the circulator (3) is connected with the input terminal of the second fiber optic splitter PBS2 (6), the second light Two output ends of fine beam splitter PBS2 (6) are connected by optical fiber with the collection terminal that the number with optical detector adopts card (7)；

The number with optical detector adopts card (7) and is electrical connected by signal wire and the microcomputer (8) with display function.

2. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the Polarization Controller (2) is electric tuning LN Polarization Controller.

3. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the Polarization Controller (2) is to squeeze polarization maintaining optical fibre formula, and the polarization axle of the direction of extrusion and polarization maintaining optical fibre is at 45 °.

4. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, it is that iDAQ6009 number adopts card that the number with optical detector, which adopts card (8),.

5. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the light field of the light of the fiber coupler is E_i, i=1,2,3,4, the light field of the port of fiber coupler output is E′_i, i=1,2,3,4, the matrix description of the characteristic 4x4 of fiber coupler are as follows:

6. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the fiber optic loop contains existing mode coupling, and can calculate nonreciprocal rotation phase shift, i.e. fiber optic loop Clockwise transmission matrix is expressed as:

E′₄=FE₃,

Wherein, u₂It illustrates the mode coupling of fiber optic loop, is not 0,For clockwise phase shift, the counterclockwise transmission of the fiber optic loop Matrix are as follows:Wherein,At this point, since space coordinate and start time all change, then:ClaimFor the mirror image matrix of F.WhereinFor phase shift counterclockwise.When optical fibre gyro rotation, Nonreciprocal phase shift will be generated, i.e.,

Angular velocity is calculated according to this formula

7. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that: describing the matrix of fibre characteristic

In two element u₁,u₂All it is plural number, sets u₁=a+ib, u₂=c+id.

8. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, Be characterized in that, using the Polarization Controller (2) constantly between the direction x linear polarization and the direction y linear polarization it is continuous Change, to be constantly changing the polarization state for being input to the sagnac interferometer (4), and constantly records two polarizations point The output power of beam device.

9. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 8, It is characterized in that, according to the output power of first, second fibre optic polarizing beam splitter PBS1, PBS2 of record (4 amounts), using as follows Formula is calculated angular speed by machine solution

Wherein

In formula, variable P indicates power, and the meaning of label is that subscript indicates the polarization direction of output, and subscript indicates the polarization of input Direction, without the output power for indicating PBS2 is skimmed, with the output power for skimming expression PBS1.

10. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the fiber optic loop is general single mode fiber.

11. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the fiber optic loop is polarization maintaining optical fibre.

12. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the photo-coupler is general single mode fiber coupler.

13. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the photo-coupler is polarization-maintaining fiber coupler.

14. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, it is guarantor that the input terminal of described first, second fibre optic polarizing beam splitter PBS1, PBS2, which are general single mode fiber output end, Polarisation is fine.

15. there is the optical fibre gyro new construction detected based on both-end polarization state in tolerance mode coupling according to claim 1, It is characterized in that, the input terminal and output end of described first, second fibre optic polarizing beam splitter PBS1, PBS2 are the guarantor of polarization maintaining optical fibre Inclined fibre optic polarizing beam splitter.

Technical field

The present invention relates to technical field of optical fiber sensing, more particularly to tolerance mode coupling is existed and is detected based on both-end polarization state Optical fibre gyro new construction.

Background technique

Gyroscope is a kind of rotation sensor, the rotational angular velocity for carrier where measuring it.Gyroscope is extensive Apply the guidance in various aircraft and weapon, the fields such as industry and military a variety of accurate measurements.Common gyroscope has three Seed type: mechanical gyroscope, lasergyro and fibre optic gyroscope.The two is all optical gyroscope afterwards.Optical gyroscope has knot The features such as structure is compact, high sensitivity, but stability is not as good as some modern mechanical gyros.Due to the needs of application, novel top Spiral shell instrument should have high sensitivity and stability, lower cost and power consumption and the features such as small in size.

Current optical fibre gyro is to be detected based on single polarization state, for example the input of the direction x, the direction x detect.Currently, being It improves the precision of polarization maintaining optical fibre gyro and reduces null offset, use feedback technique, harmonic technology and various compensation skills Art, it may be said that accomplished ultimate attainment, and the requirement for polarization-maintaining fiber coil is more and more harsher, for example mode coupling, stress will By stringent screening, this leads to cost increase, and the benefit brought is unobvious.In other words, by the guarantor for improving fiber optic loop The characteristic of polarisation fibre improves the performance of gyro, this road has gone to the end substantially.Then, we will change thinking, instead Its road and go it.Since optical fiber mode coupling is a kind of objective reality, we should just tolerate it, therefore, it is proposed that a kind of appearance Bear mode coupling and there is the optical fibre gyro new construction detected based on both-end polarization state.

Summary of the invention

The purpose of the present invention is to solve disadvantage existing in the prior art, and the tolerance mode coupling proposed exists and is based on The optical fibre gyro new construction of both-end polarization state detection.

To achieve the goals above, present invention employs following technical solutions:

There is the optical fibre gyro new construction that detect based on both-end polarization state in design tolerance mode coupling, including including light source, inclined Sagnac interferometer that controller, circulator, photo-coupler and the fiber optic loop of shaking are constituted, the first fibre optic polarizing beam splitter PBS1, Second fibre optic polarizing beam splitter PBS2, the number with optical detector adopt card, microcomputer；

The output end of the light source is connected by optical fiber with the input terminal of Polarization Controller, the output of the Polarization Controller End is connected with the first port of circulator；

The input for the sagnac interferometer that the second port of the circulator and the photo-coupler and fiber optic loop are constituted End is connected；The output end of the sagnac interferometer is connected with the input terminal of the first fiber optic splitter PBS1, the first optical fiber point Two output ends of beam device PBS1 are connected by optical fiber with the collection terminal that the number with optical detector adopts card；

The third port of the circulator is connected with the input terminal of the second fiber optic splitter PBS2, the second fiber beam splitting Two output ends of device PBS are connected by optical fiber with the collection terminal that the number with optical detector adopts card；

The number adopts card and is electrical connected by signal wire and the microcomputer with display function.

Preferably, the Polarization Controller is electric tuning LN Polarization Controller.

Preferably, the Polarization Controller is to squeeze polarization maintaining optical fibre formula, the polarization axle of the direction of extrusion and polarization maintaining optical fibre at 45°。

Preferably, it is that iDAQ6009 number adopts card that the number with optical detector, which adopts card,.

Preferably, the light field of the light of the fiber coupler is E_i, i=1,2,3,4, the port output of fiber coupler Light field is E '_i, i=1,2,3,4, the matrix description of the characteristic 4x4 of fiber coupler are as follows:

Preferably, the fiber optic loop contains existing mode coupling, and can calculate nonreciprocal rotation phase shift, that is, The clockwise transmission matrix of fiber optic loop is expressed as:

E′₄=FE₃,

Wherein, u₂It illustrates the mode coupling of fiber optic loop, is not 0,For clockwise phase shift.

Preferably, the counterclockwise transmission matrix of the fiber optic loop are as follows:Wherein,At this point, due to Space coordinate and start time all change, then:ClaimFor the mirror image matrix of F.Wherein For phase shift counterclockwise.When optical fibre gyro rotation, nonreciprocal phase shift will be generated, i.e.,

Angular velocity is calculated according to this formula

Preferably: describing the matrix of fibre characteristic

In two element u₁,u₂All it is plural number, sets u₁=a+ib, u₂=c+id.

Preferably, using the Polarization Controller constantly between the direction x linear polarization and the direction y linear polarization constantly Change, to be constantly changing the polarization state for being input to the sagnac interferometer, and constantly record the first, second light The output power of fine polarization beam apparatus PBS1, PBS2.

Preferably, according to the output power of first, second fibre optic polarizing beam splitter PBS1, PBS2 of record (4 amounts), benefit Angular speed is calculated by machine solution with following formula

Wherein

Variable P indicates power in formula, and the meaning of label is that subscript indicates the polarization direction of output, and subscript indicates input Polarization direction, without the output power for indicating PBS2 is skimmed, with the output power for skimming expression PBS1.

Preferably, the fiber optic loop is general single mode fiber；

Preferably, the fiber optic loop is polarization maintaining optical fibre；

Preferably, the photo-coupler is general single mode fiber coupler；

Preferably, the photo-coupler is polarization-maintaining fiber coupler；

Preferably, the input terminal of described first, second fibre optic polarizing beam splitter PBS1, PBS2 are general single mode fiber output End is polarization maintaining optical fibre；

Preferably, the input terminal of described first, second fibre optic polarizing beam splitter PBS1, PBS2 and output end are polarization-maintaining light Fine polarization maintaining optical fibre polarization beam apparatus；

There is the optical fibre gyro new construction detected based on both-end polarization state, beneficial effect in tolerance mode coupling proposed by the present invention Be: the present invention and traditional mode coupling for pursuing reduction optical fiber simply are on the contrary, tolerate the presence of optical fiber mode coupling, by continuous It is from x-polarisation to y-polarisation or on the contrary to change input, and obtains different output works from the output end of two polarization beam apparatus respectively Rate calculates the change rate of nonreciprocal phase shift and nonreciprocal phase shift then using Quaternion Theory and the formula of other derivations (i.e. angular speed) can be improved detection accuracy, reduce to realize the energy supply of optical fibre gyro under the conditions of tolerance mode coupling is existing Null offset.

Detailed description of the invention

Attached drawing is used to provide further understanding of the present invention, and constitutes part of specification, with reality of the invention It applies example to be used to explain the present invention together, not be construed as limiting the invention.In the accompanying drawings:

Fig. 1 is schematic structural view of the invention；

Fig. 2 is the schematic illustration of coupler in the present invention.

In the figure, it is marked as 1, light source, 2, Polarization Controller, 3, circulator, 4, Sagnac interferometer, the 5, first optical fiber point Beam device PBS1, the 6, second fiber optic splitter PBS2,7, the number with optical detector adopt card, 8, microcomputer, 10, first port, and 11, Two-port netwerk, 12, third port.

Specific embodiment

Present invention will be further explained below with reference to specific examples.These embodiments are merely to illustrate the present invention and do not have to In limiting the scope of the invention.In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, art Language " being equipped with ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or integrally connect It connects；It can be mechanical connection, be also possible to be electrically connected；It can be directly connected, can also indirectly connected through an intermediary, it can To be the connection inside two elements.For the ordinary skill in the art, above-mentioned term can be understood with concrete condition Concrete meaning in the present invention.

Now in conjunction with Figure of description, the design feature that the present invention will be described in detail.

Referring to Fig. 1, the existing optical fibre gyro new construction based on the detection of both-end polarization state of mode coupling, including light source are tolerated (1), sagnac interferometer (4), the first optical fiber of Polarization Controller (2), circulator (3), photo-coupler and fiber optic loop composition Polarization beam apparatus PBS1 (5), the second fibre optic polarizing beam splitter PBS2 (6), the number with optical detector adopt card (7), microcomputer (8)；

The output end of light source (1) is connected by optical fiber with the input terminal of Polarization Controller (2), Polarization Controller (2) it is defeated Outlet is connected with the first port (10) of circulator (3)；

The sagnac interferometer (4) that the second port (11) of circulator (3) is constituted with photo-coupler with fiber optic loop it is defeated Enter end to be connected；The output end of sagnac interferometer (4) is connected with the input terminal of the first fiber optic splitter PBS1 (5), the first light Two output ends of fine beam splitter PBS1 (5) are connected by optical fiber with the collection terminal that the number with optical detector adopts card (8)；

The third port (12) of circulator (3) is connected with the input terminal of the second fiber optic splitter PBS2 (6), the second optical fiber point Two output ends of beam device PBS2 (6) are connected by optical fiber with the collection terminal that the number with optical detector adopts card (7)；

Number with optical detector adopts card (7) and is electrical connected by signal wire and the microcomputer (8) with display function.

Furtherly, Polarization Controller (2) is electric tuning LN Polarization Controller.

Furtherly, Polarization Controller (2) is to squeeze polarization maintaining optical fibre formula, the polarization axle of the direction of extrusion and polarization maintaining optical fibre at 45°。

Furtherly, the light field of the light of fiber coupler is E_i, i=1,2,3,4, the light of the port output of fiber coupler Field is E '_i, i=1,2,3,4, the matrix description of the characteristic 4x4 of fiber coupler are as follows:

Furtherly, fiber optic loop contains existing mode coupling, and can calculate nonreciprocal rotation phase shift, i.e. optical fiber The clockwise transmission matrix of ring is expressed as:

Wherein, u₂It illustrates the mode coupling of fiber optic loop, is not 0,For clockwise phase shift.

The counterclockwise transmission matrix of fiber optic loop are as follows:Wherein,At this point, due to space coordinate and when Between starting point all change, then:ClaimFor the mirror image matrix of F.WhereinFor phase counterclockwise It moves.When optical fibre gyro rotation, nonreciprocal phase shift will be generated, i.e.,

Angular velocity is calculated according to this formula

The matrix of fibre characteristic is described

In two element u₁,u₂All it is plural number, sets u₁=a+ib, u₂=c+id.(6)

Furtherly, using Polarization Controller (2) constantly between the direction x linear polarization and the direction y linear polarization not Disconnected change, to be constantly changing the polarization state for being input to the sagnac interferometer (4), and constantly record first, The output power of second fibre optic polarizing beam splitter PBS1, PBS2.

Furtherly, according to the output power of first, second fibre optic polarizing beam splitter PBS1, PBS2 of record (4 amount), Angular speed is calculated by machine solution using following formula

Wherein

In formula, variable P indicates power, and the meaning of label is that subscript indicates the polarization direction of output, and subscript indicates input Polarization direction, without the output power for indicating PBS2 is skimmed, with the output power for skimming expression PBS1.

Furtherly, fiber optic loop is general single mode fiber.

Furtherly, fiber optic loop is polarization maintaining optical fibre.

Furtherly, photo-coupler is general single mode fiber coupler.

Furtherly, photo-coupler is polarization-maintaining fiber coupler.

Furtherly, the input terminal of first, second fibre optic polarizing beam splitter PBS1, PBS2 is general single mode fiber output end For polarization maintaining optical fibre.

Furtherly, the input terminal of first, second fibre optic polarizing beam splitter PBS1, PBS2 and output end are polarization maintaining optical fibre Polarization maintaining optical fibre polarization beam apparatus.

It is at least birefringent in the presence of 3 kinds in fiber optic loop；

It (1) is the birefringent of birefringent filters direction with the polarization principal axis of polarization maintaining optical fibre (fast axle or slow axis): this double Refraction is from the technical measures taken to make polarization maintaining optical fibre, and if geometry is birefringent, stress birfringence, both are two-fold It is all intrinsic birefringent for penetrating.Meanwhile when the polarization principal axis of lateral stress alignment polarization maintaining optical fibre, caused birefringent increase Or reduce.

(2) using poincare sphere s2 axis as the birefringent of birefringent filters direction: this birefringent to mostly come from lateral stress It is misaligned elasto-optical effect and mode coupling when polarization maintaining optical fibre main shaft, and because of mode coupling caused by optic fibre turning etc..Due to polarization-maintaining Optical fiber during drawing, can nature torsion, will be reversed once every about 10m, therefore, it is this it is birefringent be naturally occurring 's.Currently, mode coupling caused by the mainly crosswise spots stress that white light interferometer can measure.

(3) optical activity: quartz is that naturally have active material, and polarization direction is just about in the length of 30-40mm It may be rotated by 90 °.The optical activity of silica fibre, there is presently no studied well.In addition to this, the natural torsion of optical fiber The change for also resulting in polarization direction under absolute coordinate system is equivalent to and introduces an optical activity.

Meet vector superposed principle by birefringent filters, then, setting

Wherein unit vectorIts three deflections are respectively as follows:

Again due to a²+b²+d²+c²=1, a=cos θ can be enabled,

It finally obtains:

Wherein, vectorIt is exactly the total birefringent filters of optical fiber.

The corresponding quaternary number of 4 inversion matrix of fiber optic loop,

By

It obtains, a₀=a, a₁=ib, a₂=-id, a₃=ic,

It is rewritten as quaternary number, can be obtained:

Inverting quaternary number and positive quaternary number difference are birefringent caused by mode coupling to have done inverting；

Setting

Wherein, unit vectorIts three deflections are respectively as follows:

Again due to a²+b²+d²+c²=1, a=cos θ can be enabled,

It finally obtains