CN101017222A - Online alignment device of Y-type waveguide chip and polarization maintaining fiber and online alignment method thereof - Google Patents

Abstract

This invention discloses one Y waveguide chip and ensures bias fiber online alignment method, wherein, the device is set with light source, bias fiber, Y waveguide chip, light spectrum device, computer, pair axis feedback module and executive structure to rotate fiber. The invention method comprises the following steps: using light source emission light through Y wave guide chip to connect D point spectrum by the device and to analyze relative function information by use of feedback module; then using said relative function information to analyze Y wave guide chip and the bias fiber and feedback information R to executive structure.

Description

Y waveguide chip and polarization maintaining optical fibre are online to shaft device and online to the axle method

Technical field

The present invention relates to a kind of to the online device to axle of Y waveguide chip and polarization maintaining optical fibre and online to the axle method.

Background technology

Y waveguide is a vitals in the interfere type closed-loop fiber optic gyroscope, and it is at LiNbO ₃Utilize the proton exchange method to obtain to be similar to the effect of single polarization guided wave on the substrate, only allow the TE mould to pass through, and stop the TM mould to pass through, therefore have very high polarization and suppress ability.Polarization maintaining optical fibre 3 as the input tail optical fiber of Y waveguide chip 4 must with its fully to axle, the fast and slow axis that is polarization maintaining optical fibre 3 aims at fully with the fast and slow axis of Y waveguide chip 4 that (fast axle is defined as the x axle, slow axis is defined as y), the high polarization that so just can give full play to Y waveguide chip 4 suppresses ability, if and polarization maintaining optical fibre 3 can not be well to axle with Y waveguide chip 4, will bring bigger polarization cross coupling in the optical fibre gyro input channel, influence the degree of modulation of the Output optical power and the spectrum thereof of Y waveguide chip 4, thereby optical fibre gyro is brought certain influence.

At present, the used Y waveguide of internal optical fiber gyro input tail optical fiber all is to go to adjust angle artificially at the relative position that inclined to one side tail optical fiber two stressed zones and Y waveguide chip xsect are protected in microscopically utilization input to the axle method, can not realize that like this online in real time is to axle, and because the shape of Stress Profile for Polarization-Maintaining district and Y waveguide chip is undesirable, thereby caused the axle precision not high, efficient is low, and consistance is poor.

Summary of the invention

The objective of the invention is to propose a kind of Y waveguide chip and online method of polarization maintaining optical fibre of being applicable to axle, be to utilize the light source emergent light through behind the Y waveguide, gather the spectrum of tie point D by spectrometer, and parse its corresponding coherence function information with computing machine and go to estimate Y waveguide chip and its input tail optical fiber angle axle, and the shaft angle degree is fed back to topworks with described, can realize that Y waveguide chip and polarization maintaining optical fibre are online to axle.

A kind of Y waveguide chip of the present invention and polarization maintaining optical fibre are online to shaft device, include light source, polarization maintaining optical fibre, Y waveguide chip, spectrometer, computing machine, to the axle feedback module be used to topworks that polarization maintaining optical fibre is rotated; One end of light source tail optical fiber and polarization maintaining optical fibre is fused to fusing point A with 45 °, the polarization maintaining optical fibre other end and Y waveguide chip to axle in Coupling point B, Y waveguide tail optical fiber and spectrometer are connected in tie point D, spectrometer utilizes the GPIB capture card to be connected with computing machine, computing machine is connected with topworks, and topworks acts on Coupling point B.Described topworks is used for after receiving computing machine output driving command polarization maintaining optical fibre being rotated.Described computing machine is used for the spectral information of real-time collection is carried out the coherence function parsing, obtains axle feedback information R, and acts on described topworks.Described the axle feedback module is formed by resolving coherence function unit, peak-seeking unit, peak value comparing unit; The coherence function γ (n) that described peak-seeking unit goes out according to described parsing coherence function unit resolves carries out the secondary peak search and obtains secondary peak positional information D respectively _n, secondary peak amplitude information A _n, then with described secondary peak positional information D _n, described secondary peak amplitude information A _nIn described peak value comparing unit, carry out ratio and resolve acquisition axle feedback information R.

A kind of Y waveguide chip of the present invention and polarization maintaining optical fibre are online to the axle method, have following to the axle step:

The first step: spectrometer is exported to the spectrum of the light source emergent light of collection described to the axle feedback module, described the axle feedback module is parsed the coherence function γ (A) of light source emergent light behind fusing point A to the spectral information that receives in resolving the coherence function unit, then described coherence function γ (A) is carried out the secondary peak search in the peak-seeking unit, obtain light source time peak amplitude A (A) and light source time peak position D (A) on the light source coherence function γ (A);

Second step: spectrometer is exported to the spectrum of the tail optical fiber output light of the Y waveguide chip of collection described to the axle feedback module, described the axle feedback module is parsed the coherence function γ (D) of light source emergent light behind polarization maintaining optical fibre, Y waveguide chip, Y waveguide tail optical fiber, tie point D to the spectral information that receives in resolving the coherence function unit, then the coherence function γ (D) behind the described Y waveguide is carried out the secondary peak search in the peak-seeking unit, the coherence function γ (D) behind the acquisition Y waveguide goes up Y waveguide time peak amplitude A (D) and Y waveguide time peak position D (D);

The 3rd step: light source time peak position D (A) and Y waveguide time peak position D (D) are carried out the position relatively in the peak value comparing unit, go up at the coherence function γ (D) behind the Y waveguide and obtain four secondary peaks different, promptly at time t with the position on the light source coherence function γ (A) ₁The time the first secondary peak P ₁, at time t ₂The time the second secondary peak P ₂, at time t ₃The time the P of peak for the third time ₃, at time t ₄The time the 4th secondary peak P ₄At time t ₁The time coherence function γ (D) amplitude be A ₁, at time t ₂The time coherence function γ (D) amplitude be A ₂, at time t ₃The time coherence function γ (D) amplitude be A ₃, at time t ₄The time coherence function γ (D) amplitude be A ₄

Wherein: t ₁: t ₂: t ₃: t ₄=| L ₁-L ₂|: L ₂: L ₁: L ₁+ L ₂,

$A_1:A_2:A_3:A_4=$

$E_x{E}_y=\sin \left(2{\mathrm{\θ}}_B\right){\sin }^2{\mathrm{\θ}}_A\mathrm{\γ}(L_1-L_2):\left|\frac{1}{2}({E_y}^2-{E_x}^2)\sin \left({2\mathrm{\θ}}_A\right)\sin \left({2\mathrm{\θ}}_B\right)\mathrm{\γ}\left(L_2\right)\right|$

$:E_x{E}_y\sin \left({2\mathrm{\&theta;}}_A\right)\cos \left({2\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_1\right):E_x{E}_y\sin \left({2\mathrm{\&theta;}}_C\right){\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}({\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">L</figure-callout>}}_1+L_2);$

The 4th step: will handle the amplitude A that obtains through the 3rd step ₄With amplitude A ₃Carry out ratio and resolve, obtain to be used to drive topworks to axle feedback information R.

The online advantage to the axle method of Y waveguide chip of the present invention and polarization maintaining optical fibre is:

(1) by computing machine 8 with to being used in combination of axle feedback module, solved online real-time to axle, realized that Y waveguide chip 4 is connected with the robotization of polarization maintaining optical fibre 3 on production line;

(2) utilization to the axle feedback module parse to axle feedback information R, solved and on production line, be subjected to polarization maintaining optical fibre 3 stressed zone shapes to influence cause not high the axle precision, overcome the connected mode of difformity polarization maintaining optical fibre and Y waveguide chip 4 effectively;

(3) utilize the GPIB capture card to make being used of spectrometer 6 and computing machine 8, realized Y waveguide chip 4 and polarization maintaining optical fibre 3 suitability for industrialized production;

(4) the present invention adopts the analysis mode that the shaft angle degree is changed to make Y waveguide chip 4 and polarization maintaining optical fibre 3 accurately to axle, has reduced production cost and defect rate effectively.

Description of drawings

Fig. 1 is that Y waveguide chip and polarization maintaining optical fibre are in real time to the structural representation of shaft device.

Fig. 2 is that Y waveguide chip and polarization maintaining optical fibre are in real time to axle theoretical analysis synoptic diagram.

Fig. 3 is the process flow block diagram of the present invention to the axle feedback module.

Fig. 4 is the coherence function γ (A) of light source emergent light behind fusing point A.

Fig. 5 is θ _BIn the time of=15 °, the light source emergent light behind Y waveguide at the coherence function γ at tie point D place (D).

Fig. 6 is each time peak amplitude with Y waveguide and its input tail optical fiber to shaft angle degree change curve.

Fig. 7 be to axle feedback information R with Y waveguide and its input tail optical fiber to shaft angle degree change curve.

Among the figure: 1. light source 2. light source tail optical fibers 3. polarization maintaining optical fibre 4.Y waveguide chip 5.Y waveguide tail optical fibers 6. spectrometers 7. topworkies 8. computing machines

Embodiment

The present invention is described in further detail below in conjunction with accompanying drawing.

Referring to shown in Figure 1, the present invention is a kind of online to shaft device to Y waveguide chip and polarization maintaining optical fibre, includes light source 1, polarization maintaining optical fibre 3, Y waveguide chip 4, spectrometer 6, computing machine 8, to the axle feedback module be used to topworks 7 that polarization maintaining optical fibre 3 is rotated; Light source tail optical fiber 2 is fused to fusing point A with an end of polarization maintaining optical fibre 3 with 45 °, 4 pairs of axles of polarization maintaining optical fibre 3 other ends and Y waveguide chip are in Coupling point B, Y waveguide tail optical fiber 5 is connected in tie point D with spectrometer 6, spectrometer 6 utilizes GPIB capture card and computing machine 8 (in the present invention, the minimalist configuration of computing machine can be to have the 128M internal memory, the CPU of dominant frequency 900M) connects, computing machine 8 is connected with topworks 7, topworks 7 acts on Coupling point B, and (topworks 7 is used for polarization maintaining optical fibre 3 and Y waveguide chip 4 when carrying out axle, the equipment that polarization maintaining optical fibre 3 is rotated), in the described storer that the axle feedback module is stored in described computing machine 8, used the calculating and the storage capacity of computing machine 8.In the present invention, described the axle feedback module is formed by resolving coherence function unit, peak-seeking unit, peak value comparing unit; The coherence function γ (n) that described peak-seeking unit goes out according to described parsing coherence function unit resolves carries out the secondary peak search and obtains secondary peak positional information D respectively _n, secondary peak amplitude information A _n, then with described secondary peak positional information D _n, described secondary peak amplitude information A _nIn described peak value comparing unit, carry out ratio and resolve acquisition axle feedback information R.Secondary peak positional information D _nWith secondary peak amplitude information A _nThe secondary peak of expression light source 1 emergent light on the coherence function of the output light correspondence behind its tail optical fiber 2 and the Y waveguide chip 4.The coherence function that its essence is the spectrum correspondence of two place's diverse locations that spectrometer 6 is gathered compares, and obtains the amplitude and the positional information of newly-increased secondary peak.

In the present invention, described topworks 7 is used for after receiving computing machine 8 output driving command polarization maintaining optical fibre 3 being rotated; Described computing machine 8 is used for the spectral information of real-time collection is carried out the coherence function parsing, obtains axle feedback information R, and acts on described topworks 7.

In the present invention, the tail optical fiber 2 of light source 1 is a polarization maintaining optical fibre, its length L ₁Be 0.5～1.5m.The length L of polarization maintaining optical fibre 3 (being also referred to as the input tail optical fiber of Y waveguide chip 4) ₂Be 0.5～1.5m.See also shown in Figure 2, utilize light source 1 emergent light to cause the positional information of newly-increased secondary peak in the coherence function and amplitude information to estimate polarization maintaining optical fibre 3 and the coupling angle of Y waveguide chip 4 after partially, so at first must analyze the influence of each welding and coupling angle and each section fiber lengths to coherence function at Coupling point B through Y waveguide chip 4.Light source (SLD) 1 emergent light comprises TE mould and TM mould, establishes Jones's vector of light source $E_{\mathrm{IN}}=\left[\begin{array}{c}\mathrm{TE}\\ \mathrm{TM}\end{array}\right]$ , light source tail optical fiber 2 length are L ₁, light source tail optical fiber 2 is θ with 1 pair of shaft angle degree of light source chip _C, polarization maintaining optical fibre 3 length are L ₂, polarization maintaining optical fibre 3 is θ with 2 pairs of shaft angle degree of light source tail optical fiber _A(fusing point A place), polarization maintaining optical fibre 3 is θ with 4 pairs of shaft angle degree of Y waveguide chip _B(Coupling point B place), Y waveguide chip 4 amplitude extinction ratios be made as ε=-30dB, light source 1 output light is then arranged through Jones's vector behind the Y waveguide 4 $E_{\mathrm{OUT}}=\left[\begin{array}{c}\mathrm{Eo}\_x\\ \mathrm{Eo}\_y\end{array}\right]=P\&CenterDot;R\left({\mathrm{\&theta;}}_B\right)\&CenterDot;M\left(L_2\right)\&CenterDot;R\left({\mathrm{\&theta;}}_A\right)\&CenterDot;M\left(L_1\right)\&CenterDot;R\left({\mathrm{\&theta;}}_C\right)\&CenterDot;E_{\mathrm{IN}}$ , in the formula:

E _O_ x represents the amplitude of the fast axle output light of Y waveguide chip 4,

E _O_ y represents the amplitude of the slow axis output light of Y waveguide chip 4,

P represents the transmission matrix of Y waveguide chip 4, then $P=\left[\begin{array}{cc}1& 0\\ 0& \mathrm{\&epsiv;}\end{array}\right],$

R (θ _A) transmission matrix of expression fusing point A, then $R\left({\mathrm{\&theta;}}_A\right)=\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_A& \sin {\mathrm{\&theta;}}_A\\ -\sin {\mathrm{\&theta;}}_A& \cos {\mathrm{\&theta;}}_A\end{array}\right],$

R (θ _B) transmission matrix of expression Coupling point B, then $R\left({\mathrm{\&theta;}}_B\right)=\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_B& \sin {\mathrm{\&theta;}}_B\\ -\sin {\mathrm{\&theta;}}_B& \cos {\mathrm{\&theta;}}_B\end{array}\right],$

R (θ _C) transmission matrix of expression Coupling point C, then $R\left({\mathrm{\&theta;}}_C\right)=\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_C& \sin {\mathrm{\&theta;}}_C\\ -\sin {\mathrm{\&theta;}}_C& \cos {\mathrm{\&theta;}}_C\end{array}\right],$

M (L ₁) transmission matrix of expression light source tail optical fiber 2, then $M\left(L_1\right)=\left[\begin{array}{cc}{e}^{\mathrm{j\&Delta;\&beta;}{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">L</figure-callout>}}_1}& 0\\ 0& 1\end{array}\right],{\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">j</figure-callout>}}^2=-1,\mathrm{\&Delta;\&beta;}=2\mathrm{\&pi;\&Delta;n}/\mathrm{\&lambda;},$

Δ n is the poor of light source tail optical fiber 2 fast and slow axis refractive indexes, and λ is a wavelength,

M (L ₂) expression polarization maintaining optical fibre 3 transmission matrix, then $M\left(L_2\right)=\left[\begin{array}{cc}{e}^{\mathrm{j\&Delta;\&beta;}{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}& 0\\ 0& 1\end{array}\right]$ ，j ²＝-1，Δβ＝2πΔn/λ，

Δ n is the poor of polarization maintaining optical fibre 3 fast and slow axis refractive indexes, and λ is a wavelength.

Abbreviation output light Jones vector E _OUTObtain the intensity signal I of light source 1 output light through Y waveguide 4 back outputs:

$I=-E_x{E}_y\sin \left({2\mathrm{\&theta;}}_B\right){\sin }^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}(L_1-L_2)\cos \left(\mathrm{\&Delta;\&beta;}(L_1-L_2)\right)$

$+\frac{1}{2}({E_y}^2-{E_x}^2)\sin \left(2{\mathrm{\&theta;}}_A\right)\sin \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_2\right)\cos \left(\mathrm{\&Delta;\&beta;}{L}_2\right)$

${+E}_x{E}_y\sin \left({2\mathrm{\&theta;}}_A\right)\cos \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_1\right)\cos \left(\mathrm{\&Delta;\&beta;}{L}_1\right)$

${+E}_x{E}_y\sin \left({2\mathrm{\&theta;}}_B\right){\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}({\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">L</figure-callout>}}_1+L_2)\cos \left(\mathrm{\&Delta;\&beta;}({\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">L</figure-callout>}}_1+L_2)\right)---\left(1\right)$

In the formula (1):

E _xThe amplitude of expression light source tail optical fiber 2 fast axle output light, and E _x=cos θ _CTE+sin θ _CTM,

E _yThe amplitude of expression light source tail optical fiber 2 slow axis output light, and E _y=-sin θ _CTE+cos θ _CTM,

Order-E _xE _ySin (2 θ _B) sin ²θ _Aγ (L ₁-L ₂) cos (Δ β (L ₁-L ₂)) be the first modulation item U,

Order $+\frac{1}{2}({E_y}^2-{E_x}^2)\sin \left(2{\mathrm{\&theta;}}_A\right)\sin \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_2\right)\cos \left(\mathrm{\&Delta;\&beta;}{L}_2\right)$ Be the second modulation item V,

Order+E _xE _ySin (2 θ _A) cos (2 θ _B) γ (L ₁) cos (Δ β L ₁) be the 3rd modulation item W,

Order+E _xE _ySin (2 θ _B) cos ²θ _Aγ (L ₁+ L ₂) cos (Δ β (L ₁+ L ₂)) be the 4th modulation item Z,

γ (L ₁-L ₂) be that light source coherence function γ (A) is at time t ₁The time size,

γ (L ₂) be that light source coherence function γ (A) is at time t ₂The time size,

γ (L ₁) be that light source coherence function γ (A) is at time t ₃The time size,

γ (L ₁+ L ₂) be that light source coherence function γ (A) is at time t ₄The time size.

By formula (1) as can be known, the spectrum of light source 1 emergent light described four modulation item (U, V, W and Z) occur by Y waveguide 4 backs, by inverse fourier transform spectrum transform is become the coherence function γ (D) behind the Y waveguide on the time domain, then these four modulation item are reflected in corresponding four the secondary peak P of appearance of coherence function γ (D) meeting of going up ₁, P ₂, P ₃, P ₄, its distance from main peak is made as D respectively ₁, D ₂, D ₃, D ₄, its size is made as A respectively ₁, A ₂, A ₃, A ₄, then:

D ₁∶D ₂∶D ₃∶D ₄＝|L ₁-L ₂|∶L ₂∶L ₃∶(L ₁+L ₂) (2)

$A_1:A_2:A_3:A_4=$

$E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_B\right){\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}(L_1-L_2):\left|\frac{1}{2}({E_y}^2-{E_x}^2)\sin \left(2{\mathrm{\&theta;}}_A\right)\sin \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_2\right)\right|$

$:E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_A\right)\cos \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_1\right):E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_C\right){\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}({\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">L</figure-callout>}}_1+L_2)---\left(3\right)$

By formula (2), formula (3) as can be known, when light source tail optical fiber 2 and one timing of polarization maintaining optical fibre 3 length, the position of each secondary peak will be fixed on the coherence function, and the coupling angle of fusing point A, Coupling point B and Coupling point C only can influence time peak amplitude, and the coupling angle is arranged ${\mathrm{\&theta;}}_B=\frac{1}{2}\mathrm{arctg}(R\&CenterDot;2\mathrm{tg}{\mathrm{\&theta;}}_A\frac{\mathrm{\&gamma;}\left(L_1\right)}{\mathrm{\&gamma;}({\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">L</figure-callout>}}_1+L_2)})$ , work as L ₁And L ₂Select the suitable Δ β L that makes ₁With Δ β (L ₁+ L ₂) when the average smooth zone of light source coherence function γ (A), ${\mathrm{\&theta;}}_B\&ap;\frac{1}{2}\mathrm{arctg}(R\&CenterDot;2\mathrm{tg}{\mathrm{\&theta;}}_A)$ , wherein be to the axle feedback information $R=\frac{A_4}{{\mathrm{<figure-callout\; id="3"\; label="A"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">A</figure-callout>}}_3}$ 。Therefore can utilize peak P for the third time ₃With the 4th secondary peak P ₄Amplitude and the coupling angle θ of fusing point A _AParsing obtains the coupling angle θ of Coupling point B _R

In the present invention, Y waveguide chip 4 with polarization maintaining optical fibre 3 (the input tail optical fiber that also claims Y waveguide chip 4) online in real time to the treatment step of axle is:

The first step: spectrometer 6 is exported to the spectrum of light source 1 emergent light of collection described to the axle feedback module, the described coherence function γ (A) that the axle feedback module is parsed light source 1 emergent light to the spectral information that receives in resolving the coherence function unit, then described coherence function γ (A) is carried out the secondary peak search in the peak-seeking unit, obtain light source time peak amplitude A (A) and light source time peak position D (A) on the light source coherence function γ (A), the curve of perfect light source coherence function γ (A) and time t as shown in Figure 4, among the figure, light source coherence function γ (A) except main peak, no secondary peak.

Second step: the spectrum that spectrometer 6 is exported light with the Y waveguide tail optical fiber of gathering 5 is exported to described to the axle feedback module, the described coherence function γ (D) that the axle feedback module is parsed Y waveguide tail optical fiber 5 to the spectral information that receives in resolving the coherence function unit, then the coherence function γ (D) behind the described Y waveguide is carried out the secondary peak search in the peak-seeking unit, the coherence function γ (D) behind the acquisition Y waveguide goes up Y waveguide time peak amplitude A (D) and Y waveguide time peak position D (D).

The 3rd step: light source time peak position D (A) and Y waveguide time peak position D (D) are carried out the position relatively in the peak value comparing unit, go up at the coherence function γ (D) behind the Y waveguide and obtain four secondary peaks different, promptly at time t with the position on the light source coherence function γ (A) ₁The time the first secondary peak P ₁, at time t ₂The time the second secondary peak P ₂, at time t ₃The time the P of peak for the third time ₃, at time t ₄The time the 4th secondary peak P ₄At time t ₁The time coherence function γ (D) amplitude be A ₁, at time t ₂The time coherence function γ (D) amplitude be A ₂, at time t ₃The time coherence function γ (D) amplitude be A ₃, at time t ₄The time coherence function γ (D) amplitude be A ₄

Wherein: t ₁: t ₂: t ₃: t ₄=| L ₁-L ₂|: L ₂: L ₁: L ₁+ L ₂,

$A_1:A_2:A_3:A_4=$

$E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_B\right){\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}(L_1-L_2):\left|\frac{1}{2}({E_y}^2-{E_x}^2)\sin \left(2{\mathrm{\&theta;}}_A\right)\sin \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_2\right)\right|$

$:E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_A\right)\cos \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_1\right):E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_C\right){\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}({\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">L</figure-callout>}}_1+L_2);$

The curve of coherence function γ (D) and time t as shown in Figure 5, among the figure, coherence function γ (D) also has four secondary peaks except main peak.

The 4th step: will handle the amplitude A that obtains through the 3rd step ₄With amplitude A ₃Carry out ratio and resolve, obtain to be used to drive topworks 7 to axle feedback information R.

Embodiment

For being without loss of generality, establish the fiber lengths L of light source tail optical fiber 2 ₁=1.5m, the fiber lengths L of polarization maintaining optical fibre 3 ₂=1m, the coupling angle θ of Coupling point C _C=10 °, the welding angle θ of fusing point A _A=43 °.

(A) record light source 1 emergent light behind light source tail optical fiber 2,, described spectrum utilization " to the axle feedback module " is parsed corresponding light source coherence function γ (A), as shown in Figure 4, among the figure, except that main peak, do not have other secondary peaks to the spectrum of fusing point A.

(B) with light source tail optical fiber 2 and 3 weldings of Y waveguide input tail optical fiber, welding angle θ _A, establish polarization maintaining optical fibre 3 and Y waveguide chip 4 initially to shaft angle degree θ _R=15 °, then by spectrometer 6 test spectral, and utilize computing machine 8 and the axle feedback module is parsed coherence function γ (D) behind the Y waveguide, as shown in Figure 5, except that main peak, increased by four secondary peaks, the first secondary peak P ₁, the second secondary peak P ₂, peak P for the third time ₃With the 4th secondary peak P ₄

(C) the coherence function γ (D) behind light source coherence function γ (A) and the Y waveguide relatively parses the first secondary peak P on the coherence function γ (D) behind the Y waveguide ₁, the second secondary peak P ₂, peak P for the third time ₃With the 4th secondary peak P ₄, as shown in Figure 5, the distance of described four secondary peaks and main peak is that the position is respectively:

D ₁＝t ₁＝0.82×10 ^-12S，

D ₂＝t ₂＝1.64×10 ^-12S，

D ₃＝t ₃＝2.5×10 ^-12S，

D ₄＝t ₄＝4.15×10 ^-12S，

And D is arranged ₁: D ₂: D ₃: D ₄=| L ₁-L ₂|: L ₂: L ₁: L ₁+ L ₂=0.5: 1: 1.5: 2.5, parse then and time t ₃Pairing peak amplitude A ₃=0.29911, with time t ₄Pairing peak amplitude A ₄=0.092211, in the peak value comparing unit, carry out the ratio parsing and obtain the axle feedback information $R=\frac{A_4}{{\mathrm{<figure-callout\; id="3"\; label="A"\; filenames="A20071006417600131.png,A20071006417600141.png"\; state="\{\{state\}\}">A</figure-callout>}}_3}=0.316.$

(D) topworks 7 receive computing machine 8 output to behind the axle feedback information R, drive polarization maintaining optical fibre 3 and rotate a circle (180 °～+ 180 °), promptly to shaft angle degree θ _BBegin to change.In rotary course, four time peak positions can not change, and just size is along with to shaft angle degree θ _BChange and change, as shown in Figure 6, to the axle feedback information $R=\frac{A_4}{A_3}$ Along with as shown in Figure 7 to the variation of shaft angle degree.In this process, computing machine 8 calculates in real time to axle feedback information R, and storage.Under initialization condition, polarization maintaining optical fibre 3 rotates a circle pairing to five eigenwerts (as shown in Figure 7) are arranged in the axle feedback information, promptly to axis information R ₁, to axis information R ₂, to axis information R ₃, to axis information R ₄, to axis information R ₅Among the figure, R ₁=R ₃=R ₅＞R ₂=R ₄In the present invention, by the A of peak amplitude for the third time among Fig. 6 ₃With the coupling angle θ of Y waveguide 4 with polarization maintaining optical fibre 3 _BThe curve that changes as can be known, at coupling angle θ _BFor-180 °, 0 ° ,+180 ° the time its amplitude less than coupling angle θ _BFor-90 ° ,+amplitude 90 ° the time, and in actual use because the existence of noise causes axle feedback information R is not 0, so R ₁=R ₃=R ₆＞R ₂=R ₄≠ 0 (this relation can be seen in computer screen).Therefore, the present invention is to axis information R ₁Perhaps to axis information R ₃Perhaps to axis information R ₅Can think on the corresponding angle that Y waveguide chip 4 and polarization maintaining optical fibre 3 realized fully to axle.

In the present invention, the physical significance of symbol sees the following form:

E IN	Jones's vector of expression light source.
		E OUT	Expression light source 1 output light is called for short output light Jones vector through Jones's vector of Y waveguide 4 back outputs.
I	Expression light source 1 output light is called for short light intensity through the intensity signal of Y waveguide 4 back outputs.
		γ (n)	The coherence function that parses in the coherence function unit is resolved in expression.
D n	The expression peak-seeking carries out the secondary peak positional information that the secondary peak search obtains in the unit, is called for short the secondary peak positional information.
		A n	The expression peak-seeking carries out the secondary peak amplitude information that the secondary peak search obtains in the unit, is called for short the secondary peak amplitude information.
n	The expression collection point relates to the information of gathering fusing point A, the information of gathering tie point D in the present invention.
		R	Carry out in the expression peak value comparing unit ratio resolve obtain to the axle feedback information, be called for short the axle feedback information.
R 1	During-180 ° of expression polarization maintaining optical fibre 3 rotations to the axle feedback information, be called for short axis information R 1
		R 2	During-90 ° of expression polarization maintaining optical fibre 3 rotations to the axle feedback information, be called for short axis information R 2
R 3	During 0 ° of expression polarization maintaining optical fibre 3 rotation to the axle feedback information, be called for short axis information R 3
		R 4	During+90 ° of expression polarization maintaining optical fibre 3 rotations to the axle feedback information, be called for short axis information R 4
R 5	During+180 ° of expression polarization maintaining optical fibre 3 rotations to the axle feedback information, be called for short axis information R 5
		L 1	The length of the tail optical fiber 2 of expression light source 1 is called for short tail optical fiber length.
L 2	The length of expression polarization maintaining optical fibre 3.
		θ A	The welding angle of expression fusing point A.
θ B	Expression Coupling point B to the shaft angle degree.
		θ C	The coupling angle of the Coupling point C of expression light source chip 1 and light source tail optical fiber 2.
γ (A)	Be illustrated in the coherence function of resolving light source 1 emergent light that parses in the coherence function unit, be called for short the light source coherence function.
		γ (D)	Be illustrated in the coherence function of the tail optical fiber 5 output light of resolving the Y waveguide 4 that parses in the coherence function unit, the coherence function behind the abbreviation Y waveguide.

A (A)	Expression light source coherence function γ (A) carries out the secondary peak amplitude information that the secondary peak search obtains in the peak-seeking unit, be called for short light source secondary peak amplitude information.
		A (D)	Expression Y waveguide coherence function γ (D) carries out the secondary peak amplitude information that the secondary peak search obtains in the peak-seeking unit, be called for short Y waveguide secondary peak amplitude information.
D (A)	Expression light source coherence function γ (A) carries out the secondary peak positional information that the secondary peak search obtains in the peak-seeking unit, be called for short light source secondary peak positional information.
		D (D)	Expression Y waveguide coherence function γ (D) carries out the secondary peak positional information that the secondary peak search obtains in the peak-seeking unit, be called for short Y waveguide secondary peak positional information.
t 1	Expression tail optical fiber length L 1With polarization maintaining optical fibre L 2The polarization mode time-delay of difference correspondence, be called for short time t 1
		t 2	Expression polarization maintaining optical fibre L 2Corresponding polarization mode time-delay is called for short time t 2
t 3	Expression tail optical fiber length L 1Corresponding polarization mode time-delay is called for short time t 3
		t 4	Expression tail optical fiber length L 1With polarization maintaining optical fibre L 2The polarization mode time-delay of sum correspondence is called for short time t 4
P 1	Be illustrated in time t 1The time first secondary peak, be called for short the first secondary peak P 1
		P 2	Be illustrated in time t 2The time second secondary peak, be called for short the second secondary peak P 2
P 3	Be illustrated in time t 3The time peak for the third time, be called for short peak P for the third time 3
		P 4	Be illustrated in time t 4The time the 4th secondary peak, be called for short the 4th secondary peak P 4
A 1	Represent the first secondary peak P 1Amplitude, be called for short amplitude A 1
		A 2	Represent the second secondary peak P 2Amplitude, be called for short amplitude A 2
A 3	Represent peak P for the third time 3Amplitude, be called for short amplitude A 3
		A 3	Represent the 4th secondary peak P 4Amplitude, be called for short amplitude A 4
D 1	Represent the first secondary peak P 1Distance apart from main peak.
		D 2	Represent the second secondary peak P 2Distance apart from main peak.
D 3	Represent peak P for the third time 3Distance apart from main peak.
		D 4	Represent the 4th secondary peak P 4Distance apart from main peak.

Claims (3)

1, a kind of Y waveguide chip and polarization maintaining optical fibre are online to shaft device, include light source (1), polarization maintaining optical fibre (3), Y waveguide chip (4), topworks (7), it is characterized in that: also include spectrometer (6), computing machine (8) and be stored in computing machine (8) storer to the axle feedback module; Light source tail optical fiber (2) is fused to fusing point A with an end of polarization maintaining optical fibre (3) with 45 °, polarization maintaining optical fibre (3) other end and Y waveguide chip (4) to axle in Coupling point B, Y waveguide tail optical fiber (5) is connected in tie point D with spectrometer (6), spectrometer (6) utilizes the GPIB capture card to be connected with computing machine (8), computing machine (8) is connected with topworks (7), and topworks (7) acts on Coupling point B;

Described topworks (7) is used for after receiving computing machine (8) output driving command polarization maintaining optical fibre (3) being rotated;

Described computing machine (8) is used for the spectral information of real-time collection is carried out the coherence function parsing, obtains axle feedback information R, and acts on described topworks (7);

Described the axle feedback module is formed by resolving coherence function unit, peak-seeking unit, peak value comparing unit; The coherence function γ (n) that described peak-seeking unit goes out according to described parsing coherence function unit resolves carries out the secondary peak search and obtains secondary peak positional information D respectively _n, secondary peak amplitude information A _n, then with described secondary peak positional information D _n, described secondary peak amplitude information A _nIn described peak value comparing unit, carry out ratio and resolve acquisition axle feedback information R.

2, according to claim 1 online to shaft device, it is characterized in that: described light source tail optical fiber (2) is a polarization maintaining optical fibre, its length L ₁Be 0.5～1.5m; The length L of described polarization maintaining optical fibre (3) ₂Be 0.5～1.5m.

3, online online to the axle method to shaft device according to claim 1 is characterized in that the following step is arranged:

The first step: spectrometer (6) is exported to the spectrum of light source (1) emergent light of collection described to the axle feedback module, described the axle feedback module is parsed the coherence function γ (A) of light source (1) emergent light behind fusing point A to the spectral information that receives in resolving the coherence function unit, then described coherence function γ (A) is carried out the secondary peak search in the peak-seeking unit, obtain light source time peak amplitude A (A) and light source time peak position D (A) on the light source coherence function γ (A);

Second step: the spectrum that spectrometer (6) is exported light with the Y waveguide tail optical fiber of gathering (5) is exported to described to the axle feedback module, described the axle feedback module is parsed the coherence function γ (D) of light source (1) emergent light behind polarization maintaining optical fibre (3), Y waveguide chip (4), Y waveguide tail optical fiber (5), tie point D to the spectral information that receives in resolving the coherence function unit, then the coherence function γ (D) behind the described Y waveguide is carried out the secondary peak search in the peak-seeking unit, the coherence function γ (D) behind the acquisition Y waveguide goes up Y waveguide time peak amplitude A (D) and Y waveguide time peak position D (D);

The 3rd step: light source time peak position D (A) and Y waveguide time peak position D (D) are carried out the position relatively in the peak value comparing unit, go up at the coherence function γ (D) behind the Y waveguide and obtain four secondary peaks different, promptly at time t with the position on the light source coherence function γ (A) ₁The time the first secondary peak P ₁, at time t ₂The time the second secondary peak P ₂, at time t ₃The time the P of peak for the third time ₃, at time t ₄The time the 4th secondary peak P ₄At time t ₁The time coherence function γ (D) amplitude be A ₁, at time t ₂The time coherence function γ (D) amplitude be A ₂, at time t ₃The time coherence function γ (D) amplitude be A ₃, at time t ₄The time coherence function γ (D) amplitude be A ₄

Wherein: t ₁: t ₂: t ₃: t ₄=| L ₁-L ₂|: L ₂: L ₁: L ₁+ L ₂,

$A_1:A_2:A_3:A_4=$

$E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_B\right){\sin }^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}(L_1-L_2):\left|\frac{1}{2}({E_y}^2-{E_x}^2)\sin \left(2{\mathrm{\&theta;}}_A\right)\sin \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_2\right)\right|$

$:E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_A\right)\cos \left(2{\mathrm{\&theta;}}_B\right)\mathrm{\&gamma;}\left(L_1\right):E_x{E}_y\sin \left(2{\mathrm{\&theta;}}_C\right){\cos }^2{\mathrm{\&theta;}}_A\mathrm{\&gamma;}(L_1+L_2);$

The 4th step: will handle the amplitude A that obtains through the 3rd step ₄With amplitude A ₃Carry out ratio and resolve, obtain to be used to drive topworks (7) to axle feedback information R.

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