CN105841928A - High extinction ratio measurement method for optical fiber polarizer - Google Patents

Abstract

The invention belongs to the technical field of optical fiber measurement and relates to a high extinction ratio measurement method of an optical fiber polarizer. The high extinction ratio measurement method for an optical fiber polarizer comprises steps of respectively welding two segments of polarization maintaining optical fibers with various lengths on an input terminal and an output terminal of a Y waveguide (i.e. a high extinction ratio polarizing device to be detected) to construct a measurement assembly with a quantitative crosstalk mark; using a lumped extinction ratio tester to perform quantitative control on the extinction ratio of a welding point and recording the measurement value; setting the lengths of a polarizer pigtail, an analyzer pigtail, a high extinction ratio polarizer pigtail, and the welding polarization maintaining optical fiber; connecting the measurement assembly to the distributed optical fiber polarization crosstalk tester; and using a two-order crosstalk measurement value between the externally-connected optical fiber welding points to perform calibration and self-calibration on the extinction ratio of the polarizing device to be detected. During the measurement, the high extinction ratio measurement method of the invention can perform synchronous measurement on the crosstalk mark and the measurement peak, and avoids errors introduced by the change of the measurement environment and the member connection precision.

Description

A kind of High Extinction Ratio measuring method of optical fiber polarizer

Technical field

Present invention design belongs to technical field of optical fiber measurement, is specifically related to the High Extinction Ratio measuring method of a kind of optical fiber polarizer.

Background technology

Polarization optics is to constitute high-precision optical to measure the important component part with sensor-based system, and current optics performance is surveyed The present situation that examination falls behind with evaluation method and device, seriously hinders high-precision optical and measures the development with sensor-based system.Such as: high The chip extinction ratio of core devices Lithium metaniobate integrated waveguide manipulator (being commonly called as Y waveguide) of precision optical fiber gyro has reached More than 80dB；And conventional polarization property detecting instrument extinction ratio tester, common detection resolution is at about 50dB (according to energy definition, it is 10⁵), the Model4810 type polarization developed for dBm Optics company of the U.S. that resolution is the highest Extinction ratio measurement instrument, its measuring limit also only has 72dB.

Optical coherence domain polarimetry technology (OCDP) is a kind of high accuracy distributed polarization coupling measurement technology, and it is based on width Spectrum interference of light principle, carries out optical path compensation by scan-type optical interdferometer, it is achieved the interference between different polarization pattern, can be to partially The shake locus of crosstalk, polarization coupled signal intensity carries out high-precision measurement and analysis, and then obtains optical polarization device The important parameters such as extinction ratio, bat length.OCDP technology is as the detection side of the most promising a kind of distributed optical polarization performance Method, is widely used in the field such as polarization maintaining optical fibre manufacture, the most countershaft, the device extinction ratio test of polarization maintaining optical fibre.With other such as polarization Time domain reflection technology (POTDR), optical frequency domain reflection technology (OFDR), light coherent field reflection technology (OCDR) equal distribution Formula detection method is compared with technology, and OCDP technology has simple in construction, high spatial resolution (5～10cm), wide-measuring range (measuring several kilometers of length), super high measurement sensitivity (coupling energy-80～-100dB), super big dynamic range (10⁸～10¹⁰) etc. Advantage, is hopeful to develop into a kind of high accuracy, generalization measuring technology and system very much.Due to it the most directly and truly Describe flashlight transport behavior in optic fibre light path, so being particularly suitable for optical fibre device, assembly, and optical fibre gyro Test Deng high accuracy, superhigh precision interference-type optical fiber sensing light path and assess.

Early 1990s, France Herve Lefevre et al. [Method for the detection of polarization couplings in a birefringent optical system and application of this method to the assembling of the Components of an optical system, US Patent 4863631] make public for the first time OCDP system based on white light interference theory System, it uses super-radiance light emitting diode (SLD) as light source and space interference light path as light path measurement of correlation structure.Method Photonetics company of state have developed 125 and WIN-P 400 two kinds of model OCDP test systems of WIN-P according to this patent, main It is used for the polarization characteristic analysis of shorter (500m) and longer (1600m) polarization maintaining optical fibre.Its main performance is polarization interference spirit Sensitivity is-70dB, dynamic range is 70dB, after through improvement, sensitivity and dynamic range rise to-80dB and 80dB respectively.

2011, University Of Tianjin Zhang Hongxia et al. disclosed detection method and the detection dress of a kind of polarization extinction ratio of optical polarizer Putting (Chinese Patent Application No.: 201110052231.3), same employing space interference light path is as the core apparatus of OCDP, logical Cross the stiffness of coupling of detection Coupling point, derive polarization extinction ratio.This device be applicable to polarization maintaining optical fibre, polarization-maintaining fiber coupler, The multiple optical polarization device such as polariser.Compared with the scheme of Herve Lefevre et al., technical performance and index are close.

The same year, Yao Xiaotian of AM General photoelectricity company (General Photonics Corporation) et al. disclose a kind of for In polarization maintaining optical fibre and optical birefringence material distributed polarization interference measure all-fiber measure system (US20110277552, Measuring Distributed Polarization Crosstalk in Polarization Maintaining Fiber and Optical Birefringent Material), utilize before light path correlator increase optical path delay device, suppression polarization interference measure time spuious in vain The quantity of optical interference signals and amplitude.All-fiber can be measured the polarization interference sensitivity of system and bring up to-95dB by the method, but Dynamic range is maintained at 75dB.

2012, present invention applicant disclosed a kind of device and method (China improving optics polarization interference measurement performance Number of patent application CN201210379407.0) and all-fiber test device of a kind of optics polarization interference measurement (CN201210379406.6), use all-fiber light path correlator configuration, increase polarization beam splitting and the function that is rotatably connected online, press down System claps noise, is effectively improved measurement sensitivity, increases Faraday polarization apparatus in the correlator, increases the stability of light source, improves The utilization rate of light source power, both the above device is all applicable to the performance test of multiple polarizer.With AM General photoelectricity company Compare, while the polarization interference sensitivity of the system of measurement can being brought up to-95dB, make dynamic range be maintained at and be better than 95dB. Sensitivity, already close to measuring limit, is primarily limited to the relative intensity noise of light source.Do not change light channel structure, optimize element Under the intensity of parameter, measure sensitivity and will be unable to get a promotion further.

2013, present invention applicant proposed one and exposes thoroughly range optical coherence domain polarization measurement device (Chinese patent application Number CN201310736313.4), use multiple continuous way light path expanding element to cascade, and make the scanning optics in unit become To appearance, it is achieved light path scanning extension, suppression scanning device intensity is floated on the impact measured.The problem mainly solved is how to carry The accuracy of high polarization interference measurement and stability, measure sensitivity behaviour and do not improve.

2014, present invention applicant proposed a kind of optical coherence polarimeter (Chinese patent suppressing interaction noise Application number CN201410120901.4), use full fiber type polarization beat length device to eliminate the reflection of optics residual light, make usage The light path demodulating equipment drawing polarization apparatus overcomes the polarization decay effect in interference, effectively suppresses interaction noise；Propose with light path The optical coherence domain polarization measurement device (Chinese Patent Application No. CN201410120591.6) of scan position and velocity correction, logical Cross the correction to light path scanning, improve spatial accuracy and the detectivity of polarimeter.

Constantly promoting for the precision of polarizer performance test is the unremitting pursuit of scientific measurement, especially for High Extinction Ratio device Part (such as Y waveguide etc.) has more significance.During system building, due to device connection to be carried out, inevitable in connection Can produce nonideal defect at Dian, how weakening or correctly utilizing these defect points is a critically important content.By weldering Connect the crosstalk utilizing extinction ratio tester setting alignment angle to cause before to be marked, and the length of Reasonable polarization maintaining optical fibre, The Second Order Interferometric peak of structure High Extinction Ratio, reaches the purpose that High Extinction Ratio device is accurately measured.

The invention provides the High Extinction Ratio measuring method of a kind of optical fiber polarizer, by the length of polarization maintaining optical fibre in measurement apparatus During the welding of degree, polarization maintaining optical fibre, alignment angle monitoring, utilizes 45 ° of polarizers, polarization maintaining optical fibre, 45 ° of analyzers to connect and compose quantitatively The measurement assembly of crosstalk labelling, can realize the on-line calibration to extinction ratio and measure, reach High Extinction Ratio polarizer is carried out essence The purpose really measured.

Summary of the invention

It is an object of the invention to provide and a kind of have the advantages that precision is high, reliable and stable, can be used for high-precision optical device (Y Waveguide) the High Extinction Ratio measuring method of optical fiber polarizer accurately measured of the carrying out of polarization property measuring instrument.

The object of the present invention is achieved like this:

The High Extinction Ratio measuring method of a kind of optical fiber polarizer, in the input, defeated of the i.e. Y waveguide of High Extinction Ratio polarizer to be measured Go out end and be respectively welded the polarization maintaining optical fibre of two sections of different lengths, constitute the measurement assembly with quantitative crosstalk labelling；Collection is utilized during welding The extinction ratio of total formula extinction ratio tester butt welding contact carries out fixing quantity and records its measured value, simultaneously to polarizer tail optical fiber, inspection Device tail optical fiber, High Extinction Ratio polarizer tail optical fiber, the length of welding polarization maintaining optical fibre partially is set；Assembly will be measured and access distributed In optical fiber polarisation crosstalk test device, utilize the second order crosstalk measured value between external optical fiber pad to polarizer delustring to be measured Ratio carries out demarcating and self calibration；Comprise the steps:

(1) from Y waveguide 113 input y1 input beam, lump type extinction ratio tester is utilized to measure C point crosstalk PER_c Value；

(2) length of Y waveguide 113 outfan y2 is intercepted as l₃, the length of polarization maintaining optical fibre 115 is taken as l₂, use and protect Bonding machine partially is directed at, and polarization maintaining optical fibre 115 output beam lump type extinction ratio tester is measured in real time, the value of the extinction ratio of measurement For PER_b+PER_c；Rotational alignment angle, makes PER_bAmount reaches setting value, by Y waveguide 113 outfan y2 and polarization maintaining optical fibre 115 welding, record value PER now_b；

(3) from polarization maintaining optical fibre 115 input beam, lump type extinction ratio tester is utilized to measure D point crosstalk PER_dValue；

(4) length of the input y1 of Y waveguide 113 intercepts as l₄, the length of polarization maintaining optical fibre 114 is taken as l₅, use and protect weldering partially Pick alignment, and the output beam lump type extinction ratio tester of polarization maintaining optical fibre 114 is measured in real time, and the value of the extinction ratio of measurement is PER_d+PER_e；Rotational alignment angle, makes PER_bAmount reaches setting value, by Y waveguide 113 input y1 and polarization maintaining optical fibre 114 Welding, record value PER now_e。

(5) 45 ° of polarizers 111 are protected inclined tail optical fiber ps1,45 ° of analyzers 116 are protected the length of inclined tail optical fiber ps2 and are intercepted as l₆, l₁, the 45 ° of polarizer 111 polarization maintaining optical fibre ps1 are protected inclined tail optical fiber ps2 with 114,45 ° of analyzers 111 of polarization maintaining optical fibre and protect polarisation Fine 115 equal 0 °～0 ° alignment welding；

(6) connect wide spectrum light source to fill with signal record with power monitoring apparatus 100, light path correlator 130, polarization interference detection Put 140；

(7) open wide spectrum light source 101, regulate polarization beat length device 132 and optical scanner 133 to interference signal maximum rating, Drive light path scanning device 133, use polarization interference detection with signal recording apparatus 140 to different scanning in light path correlator 130 The data of distance measure and record, it is thus achieved that distributed polarization crosstalk measurement result, and the polarization crosstalk that record is measured in collection of illustrative plates is made an uproar The position of sound background data and each interference peaks and amplitude；

(8) being normalized interference illustration data, comparison is in position and the height of the single order interference peaks interfering main peak both sides； Intercepted length l according to known fiber optic₁、l₂、l₃、l₄、l₅、l₆, utilize relational expression:

τ=Δ n_fl

τ it is in obtaining_l1、τ_l1+τ_l2、τ_l1+τ_l2+τ_l3、τ_l4+τ_l5+τ_l6、τ_l5+τ_l6、τ_l6ρ corresponding to position_A、ρ_B、ρ_C、ρ_D、 ρ_E、ρ_FThe amplitude at peak, and to PER_bWith ρ_B、PER_cWith ρ_C、PER_dWith ρ_D、PER_eWith ρ_EValue carry out demarcating and self-correcting Standard, obtains the exact numerical at each single order crosstalk peak；

Optical path delay amount is respectively 0,Crosstalk coefficient depend on Secondary be 1, ρ_A、ρ_B、ρ_C、ρ_D、ρ_E、ρ_F；

(9) on the basis of single order interference peaks, by calculating, obtain being in τ_l1+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l4+τ_l5+τ_l6、 τ_l1+τ_l2+τ_l3+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l3+τ_l5+τ_l6、τ_l1+τ_l2+τ_l3+τ_l6ρ corresponding to position_A+ρ_D、ρ_B+ρ_D、ρ_C+ρ_D、 ρ_C+ρ_E、ρ_C+ρ_FThe size at peak, compares with position and the amplitude at the peak in collection of illustrative plates, obtains the perfect number at each second order crosstalk peak Value, is used for the demarcation to High Extinction Ratio region and self calibration；Optical path delay amount is respectively Crosstalk Coefficient is followed successively by ρ_A+ρ_D、ρ_B+ρ_D、ρ_C+ρ_D、ρ_C+ρ_E、ρ_C+ρ_F；

(10) by measuring at τ_l1+τ_l2+τ_l3+τ_l4+τ_l5+τ_l6+τ_lYI.e. peak amplitude at the outermost of interference illustration, obtains Y to be measured The exact numerical of the extinction ratio of waveguide, completes accurately to measure, optical path delay amountCrosstalk system Number is ε_chip。

45 ° of described analyzers 116 protect inclined tail optical fiber ps2, polarization maintaining optical fibre 115, Y waveguide 113 outfan y2, Y waveguide 113 Input y1,114,45 ° of polarizers 111 of polarization maintaining optical fibre protect length l of inclined tail optical fiber ps1₁、l₂、l₃、l₄、l₅、l₆Choosing Take, satisfied four square relations of plane:

1) ensure to make the single order of correspondence, second order interference peak in interference illustration be interspersed in interference illustration:

l₁≠l₆≠l₁+l₂≠l₅+l₆≠l₁+l₆

≠l₁+l₂+l₃≠l₁+l₂+l₆

≠l₁+l₅+l₆≠l₄+l₅+l₆

≠l₁+l₄+l₅+l₆≠l₁+l₂+l₃+l₆≠l₁+l₂+l₅+l₆；

≠l₁+l₂+l₄+l₅+l₆≠l₁+l₂+l₃+l₅+l₆

≠l₁+l₂+l₃+l₄+l₅+l₆

≠l₁+l₂+l₃+l₄+l₅+l₆+l_Y

2) input polarization maintaining optical fibre y1 length L of Y waveguide 113_inOptical path difference be concerned with the light path at peak more than wide spectrum light source 101 ripple L_r, it may be assumed that L_in×Δn_f>L_r, L_inInclined tail optical fiber ps1 length sum is protected for input tail optical fiber y1,114,45 ° of polarizers of polarization maintaining optical fibre, Δ nf is polarization maintaining optical fibre linear birefrigence；

3) output polarization maintaining optical fibre y2 length L of Y waveguide 113_outOptical path difference more than between the fast and slow axis of Y waveguide 113 own Optical path difference, it may be assumed that L_out×Δn_f>L_Y×Δn_Y；L_outInclined tail optical fiber ps2 is protected for output tail optical fiber y2,115,45 ° of analyzers of polarization maintaining optical fibre Length sum；L_YFor Y waveguide length, Δ n_YLinear birefrigence for Y waveguide；

4) the light path sweep limits Δ L measured

ΔL>2(L_in+L_Y+L_out)

The midpoint of light path sweep limits is the position of the peak-peak of polarization crosstalk measurement data.

Compared with prior art, the beneficial effects of the present invention is:

(1) by rationally selecting the length of polarization maintaining optical fibre, suppression light source ripple and the impact of fiber optic noise, extinction ratio is utilized to test Instrument, during building high precision testing device, is adjusted the extinction ratio of the junction point (solder joint) in polarization maintaining optical fibre, fixed Amount structure single order interference peaks, uses its Second Order Interferometric peak that High Extinction Ratio region carries out quantitative crosstalk labelling, reaches accurately to measure Purpose.

(2) when the process of measurement, crosstalk labelling can be carried out synchro measure with measuring peak, stop to measure environment change and device connects Connect the error of the introducings such as precision.

(3) utilize High Extinction Ratio device (Y waveguide) from the characteristic of the cut-off in a certain characteristic axle, while measuring, subtract The quantity at few spuious peak, improves the test accuracy of High Extinction Ratio polarizer.

(4), during making High Extinction Ratio device (Y waveguide) is measured, rigors needn't be proposed to measuring device, use inspection The conventional device such as device, polarization maintaining optical fibre partially can carry out quantitative mark, and measurement accurate to extinction ratio, for whole device to crosstalk For build simple, precision improvement is notable.

Accompanying drawing explanation

Fig. 1 is the optical principle schematic diagram of the distributed polarization interference single defect point measurement of optics；

Fig. 2 is the single polarization interference interference signal peak formed and the corresponding relation schematic diagram transmitting optical attenuation multiple；

Light beam change schematic diagram when Fig. 3 is two polarization maintaining optical fibre θ angular alignment welding；

Fig. 4 is the High Extinction Ratio instrumentation plan of optical fiber polarizer；

Fig. 5 is the measurement component diagram of quantitative crosstalk labelling；

Fig. 6 is the High Extinction Ratio measuring method flow chart of optical fiber polarizer.

Detailed description of the invention

Below in conjunction with the accompanying drawings the present invention is described further.

The invention provides a kind of optical fiber polarizer High Extinction Ratio measuring method.High Extinction Ratio polarizer (Y waveguide) to be measured Input, outfan be respectively welded the polarization maintaining optical fibre that length is different, constitute the measurement assembly with quantitative crosstalk labelling；During welding The extinction ratio utilizing lump type extinction ratio tester butt welding contact carries out fixing quantity and records its measured value, simultaneously to playing (inspection) Device tail optical fiber, High Extinction Ratio polarizer (Y waveguide) tail optical fiber, the length of welding polarization maintaining optical fibre partially is set；By above-mentioned measurement Assembly accesses in distribution type fiber-optic polarization interference test device, utilizes the second order crosstalk measured value between external optical fiber pad to treat Survey polarizer extinction ratio to carry out demarcating and self calibration, thus promote the accuracy of measurement.It is high, square that the present invention has certainty of measurement The advantages such as method is easy, are widely used in the high-precision of the optics polarization property such as polarization maintaining optical fibre, integrated waveguide manipulator (Y waveguide) Degree is measured and is analyzed.

The High Extinction Ratio measuring method of optical fiber polarizer, in input, the output of High Extinction Ratio polarizer (Y waveguide) to be measured End is respectively welded the polarization maintaining optical fibre of two sections of different lengths, constitutes the measurement assembly with quantitative crosstalk labelling；Lump is utilized during welding The extinction ratio of formula extinction ratio tester butt welding contact carries out fixing quantity and records its measured value, simultaneously to rise (inspection) inclined device tail optical fiber, High Extinction Ratio polarizer (Y waveguide) tail optical fiber, the length of welding polarization maintaining optical fibre are set；Assembly will be measured and access distributed In optical fiber polarisation crosstalk test device, utilize the second order crosstalk measured value between external optical fiber pad to polarizer delustring to be measured Ratio carries out demarcating and self calibration.Measuring process, comprises High Extinction Ratio polarizer (Y waveguide) input, outfan polarization maintaining optical fibre The selection of length and soldering angle and measurement, (inspection) device tail optical fiber length partially select, distributed polarization cross talk characteristic is measured, with And High Extinction Ratio polarizer (Y waveguide) performance parameter calculates, detailed process is:

(1) from Y waveguide input y1 input beam, lump type extinction ratio tester is utilized to measure C point crosstalk PER_cValue.

(2) length of Y waveguide outfan y2 is intercepted as l₃, the length of polarization maintaining optical fibre 115 is taken as l₂, use and protect weldering partially Pick alignment, and polarization maintaining optical fibre 115 output beam lump type extinction ratio tester is measured in real time, the value of the extinction ratio now measured For PER_b+PER_c.Rotational alignment angle, makes PER_bAmount reaches setting value (such as-30dB), now, by Y waveguide outfan Y2 welds with polarization maintaining optical fibre 115, record value PER now_b。

(3) from polarization maintaining optical fibre 115 input beam, lump type extinction ratio tester is utilized to measure D point crosstalk PER_dValue.

(4) length of the input y1 of Y waveguide intercepts as l₄, the length of polarization maintaining optical fibre 114 is taken as l₅, use and protect welding partially Machine is directed at, and the output beam lump type extinction ratio tester of polarization maintaining optical fibre 114 is measured in real time, the value of the extinction ratio now measured For PER_d+PER_e.Rotational alignment angle, makes PER_bAmount reaches setting value (such as-45dB), now, by Y waveguide input Y1 welds with polarization maintaining optical fibre 114, record value PER now_e。

(5) 45 ° of polarizers are protected inclined tail optical fiber ps1, the length of 45 ° of analyzer inclined tail optical fiber ps2 of guarantor intercepts as l₆, l₁, by 45 ° Polarizer polarization maintaining optical fibre ps1 and 114,45 ° of analyzers of polarization maintaining optical fibre protect inclined tail optical fiber ps2 equal with polarization maintaining optical fibre 115 0 °～0 ° right Quasi-welding.

(6) wide spectrum light source and power monitoring apparatus, light path correlator, polarization interference detection and signal recording apparatus are connected.

(7) opening wide spectrum light source, regulation polarization beat length device and optical scanner are to interference signal maximum rating.Driving light path is swept Retouch device, use polarization interference detection with signal recording apparatus, the data of different scanning distance in light path correlator are measured and remembered Record, it is thus achieved that distributed polarization crosstalk measurement result, the polarization crosstalk Noise Background data in collection of illustrative plates and each interference peaks measured in record Position and amplitude.

(8) being normalized interference illustration data, comparison is in position and the height of the single order interference peaks interfering main peak both sides. Intercepted length l according to known fiber optic₁、l₂、l₃、l₄、l₅、l₆, utilize relational expression:

τ=Δ n_fl (1)

τ it is in obtaining_l1、τ_l1+τ_l2、τ_l1+τ_l2+τ_l3、τ_l4+τ_l5+τ_l6、τ_l5+τ_l6、τ_l6ρ corresponding to position_A、ρ_B、ρ_C、ρ_D、 ρ_E、ρ_FThe amplitude at peak, and to PER_bWith ρ_B、PER_cWith ρ_C、PER_dWith ρ_D、PER_eWith ρ_EValue carry out demarcating and self-correcting Standard, obtains the exact numerical at each single order crosstalk peak, as shown in table 1.

Single order peak position and the amplitude relation of assembly measured by table 1

(9) on the basis of single order interference peaks, by calculating, can obtain being in τ_l1+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l4+τ_l5+τ_l6、 τ_l1+τ_l2+τ_l3+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l3+τ_l5+τ_l6、τ_l1+τ_l2+τ_l3+τ_l6ρ corresponding to position_A+ρ_D、ρ_B+ρ_D、ρ_C+ρ_D、 ρ_C+ρ_E、ρ_C+ρ_FThe size at peak, compares with position and the amplitude at the peak in collection of illustrative plates, can get the accurate of each second order crosstalk peak Numerical value, is used for the demarcation to High Extinction Ratio region and self calibration, as shown in table 2.

Second order peak position and the amplitude relation of assembly measured by table 2

(10) by measuring at τ_l1+τ_l2+τ_l3+τ_l4+τ_l5+τ_l6+τ_lY(i.e. the outermost of interference illustration) place's peak amplitude, is treated Survey the exact numerical of the extinction ratio of Y waveguide, complete accurately to measure, as shown in table 3.

The position of table 3 Y waveguide to be measured interference peaks and amplitude relation

45 ° of analyzers protect inclined tail optical fiber ps2, polarization maintaining optical fibre 115, Y waveguide 113 outfan y2, the input y1 of Y waveguide, Length l of inclined tail optical fiber ps1 protected by 114,45 ° of polarizers of polarization maintaining optical fibre₁、l₂、l₃、l₄、l₅、l₆Choose, following four must be met Individual side's relation of plane:

(1) when length selects, for preventing peak value overlap from causing interference with judgement, need to meet the relational expression such as not in formula (2), I.e. to ensure to make the single order of correspondence, second order interference peak in interference illustration be interspersed in interference illustration:

$\begin{array}{c}{l}_1\≠l_6\≠l_1+l_2\≠l_5+l_6\≠l_1+l_6\\ \≠l_1+l_2+l_3\≠l_1+l_2+l_6\\ \≠l_1+l_5+l_6\≠l_4+l_5+l_6\\ \≠l_1+l_4+l_5+l_6\≠l_1+l_2+l_3+l_6\≠l_1+l_2+l_5+l_6\\ \≠l_1+l_2+l_4+l_5+l_6\≠l_1+l_2+l_3+l_5+l_6\\ \≠l_1+l_2+l_3+l_4+l_5+l_6\\ \≠l_1+l_2+l_3+l_4+l_5+l_6+l_Y\end{array}---\left(2\right)$

(2) input polarization maintaining optical fibre length L of Y waveguide_inOptical path difference be concerned with the light path L at peak more than wide spectrum light source ripple_r, it may be assumed that L_in×Δn_f>L_r(L_inInclined tail optical fiber ps1 length sum, Δ n is protected for input tail optical fiber y1,114,45 ° of polarizers of polarization maintaining optical fibre_fFor Polarization maintaining optical fibre linear birefrigence).

(3) output polarization maintaining optical fibre length L of Y waveguide_outOptical path difference more than the optical path difference between the fast and slow axis of Y waveguide own, it may be assumed that L_out×Δn_f>L_Y×Δn_Y(L_outInclined tail optical fiber ps2 length sum is protected for output tail optical fiber y2,115,45 ° of analyzers of polarization maintaining optical fibre, L_YFor Y waveguide length, Δ n_YLinear birefrigence for Y waveguide).

(4) the light path sweep limits Δ L measured needs to meet

ΔL>2(L_in+L_Y+L_out) (3)

Further, the midpoint of light path sweep limits is chosen as the position of peak-peak of polarization crosstalk measurement data as far as possible.

For the theta alignment of B, E 2, due to before system test, the extinction ratio data of C, D 2 by disappearing Light measures (according to the feature of Y waveguide, typically at about-40dB) than tester, can according to the size of C, D 2 to B, The extinction ratio that E is 2 is set, and utilizes B, C, D, E that single order interference peaks and the Second Order Interferometric peak of interference point are formed peak value Gradient.As being respectively-37dB ,-33dB in the extinction ratio of C, D 2, now, B, E 2 is optional when welding PER_b=-30dB, PER_e, so, PER can be there is by correspondence in interference peaks position and amplitude table in=-45dB_b+PER_d=-63dB, PER_c+PER_d=-70dB, PER_c+PER_eHigh Extinction Ratio interference peaks known to many positions of=-82dB and amplitude, is used for measuring dress That puts is calibrated.

The present invention is the demarcation to optical coherence domain polarization test system (OCDP) based on white light interference theory and measurement apparatus. The operation principle of OCDP as it is shown in figure 1, as a example by the performance test of polarization maintaining optical fibre, wide spectrum light source the high stable wide range sent Polarized light 301 is injected into the slow axis (during fast axle, principle is identical) of the polarization maintaining optical fibre 321 of certain length.Due in polarizer All in strict accordance with protecting off-axis transmission, nonideal defect point or connection can be there is in the most all of light.Flashlight is along slow axis During transmission, when flashlight is transferred to defect point 311, a part of light energy in slow axis will be coupled in orthogonal fast axle, Forming coupled light beam 303, remaining transmitting beam 302 is still transmitted along slow axis.Optical fiber exist linear birefrigence Δ n (such as: 5×10^-4), make the refractive index of slow axis more than fast axle refractive index, when the other end of optical fiber exports (transmission range is l), then pass An optical path difference Δ nl will be there is in the defeated transmission light 302 at slow axis and transmission between the coupling light 303 of fast axle.Above-mentioned light beam leads to Cross pad or rotary connecting joint 312, enter in light path correlator 330.In light path correlator 330, polarizing beam splitter mirror 332, stationary mirror 334, mobile mirror 338 form a Michelson optical interdferometer.Light beam 302 and 303 warp Two parts in light path correlator 330 is divided into fixed arm and scan arm after crossing polarizing beam splitter mirror 332.The light of transmission in fixed arm Detector 339 is arrived after the reflection of stationary mirror 334；Anti-through mobile mirror 338 of light of transmission in scan arm Also arriving at detector 339 after penetrating, two parts light converges in formation white light interference signal on detector 339, is received and by light Signal is converted to the signal of telecommunication.This signal, after signal demodulating circuit 341 processes, is sent in metering computer 342；Meter Calculation machine 342 to be the most also responsible for controlling mobile mirror 338 and realize light path scanning.

Under the control of metering computer 342, the mobile mirror 338 of Michelson interferometer makes the optical path difference of interferometer two-arm From Δ nl through zero passage, scanning is to-Δ nl, as shown in Figure 2:

(1) when optical path difference is equal to Δ nl, in scan arm, light 204 mates with light in fixed arm 201, then produce white light and do Relating to signal, its peak amplitude isIt with defect point couple amplitude factor and the intensity of light source is directly proportional.

(2) when optical path difference is equal to 0, scan arm mates with light 202 with light 201, light 206 with light in fixed arm 205, Then producing white light interference signal, its peak amplitude is I_coupling∝I₀, it is directly proportional to the intensity of light source.

(3) when optical path difference is equal to Δ nl, in scan arm, light 207 mates with light in fixed arm 202, then produce white light and do Relating to signal, its peak amplitude isIt with defect point couple amplitude factor and the intensity of light source is directly proportional.

Interference signal is processed, after normalization, is converted into dB value, by interference peaks with this amplitude and the detection of distance, The important informations such as the position and the extinction ratio that i.e. can get polarization maintaining optical fibre shortcoming.

Structure is demarcated to the size at peak, can be by the soldering angle of polarization maintaining optical fibre be adjusted.Such as Fig. 3.Protect partially in incidence The polarized light of fast axle transmission in optical fiber, such as Fig. 3 (a)；When the alignment angle of incident polarization maintaining optical fibre with outgoing polarization maintaining optical fibre is θ, Light beam can produce component, such as Fig. 3 (b) on two feature axis of outgoing optical fiber；When outgoing polarization maintaining optical fibre transmits, the ratio of two axles Value relation is tan²θ, such as Fig. 3 (c).Being equivalent to the extinction ratio of structure at solder joint is-10log₁₀[tan²θ](dB).Pass through The alignment angle of polarization maintaining optical fibre is adjusted, to obtain different " crosstalks ", by changing different polarization maintaining optical fibre alignment angle Obtain different crosstalk peak values.

From interference illustration, the interference peaks of main peak both sides is all that flashlight is formed with coupling interference of light, for once couples The participation of light, therefore referred to as single order interference peaks.Single order interference peaks is utilized can little extinction ratio (0～-40dB) to be entered in this patent Row labelling accurately.For High Extinction Ratio (-40～-100dB) region, owing to directly being welded by polarization maintaining optical fibre during theta alignment Angle precision is difficult to meet the requirement of demarcation, at this moment needs to construct Second Order Interferometric peak on the basis of single order interference peaks.Doing of second order Relating to the corresponding big extinction ratio in peak, its position and height are associated with length and the alignment angle of the polarization maintaining optical fibre forming single order interference peaks, Polarization maintaining optical fibre alignment angle precision needn't be made rigors, system can be made accurate labelling.Before existing alignment precision Put, i.e. may utilize high-order interference peaks and complete the Accurate Calibration of little extinction ratio (-40dB～-100dB), it is achieved the school of test system Accurate.

As a example by Fig. 5, in the measurement assembly of quantitative crosstalk labelling, the coupling of different qualities axle can be there is through each solder joint light, The exponent number of the number of times correspondence crosstalk of coupling.Only allow due to Y waveguide the light of fast axle to pass through, get rid of from the slow axis situation by light. Single order is interfered, the interference that i.e. 0 rank light beam (Straight-Through Beam of crosstalk does not occur) is formed with single order crosstalk light beam；For Second Order Interferometric, can be divided into two kinds of situations: the interference that (1) 0 rank light beam is formed with second order crosstalk light beam；(2) single order crosstalk and The interference that rank crosstalk is formed.When single order, Second Order Interferometric, its interference formula can abbreviation be:

$\begin{array}{c}\frac{I\left(\mathrm{\τ}\right)}{I\left(0\right)}=R_x\left(\mathrm{\τ}\right)+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}){\mathrm{\ρ}}_A+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}){\mathrm{\ρ}}_B+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}-{\mathrm{\τ}}_{l_3}){\mathrm{\ρ}}_C\\ +R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_4}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_D+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_E+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_F\\ +R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}-{\mathrm{\τ}}_{l_3}-{\mathrm{\τ}}_{l_4}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}-{\mathrm{\τ}}_{l_Y}){\mathrm{\ϵ}}_{chip}\\ +R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_4}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_A{\mathrm{\ρ}}_D+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}-{\mathrm{\τ}}_{l_4}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_B{\mathrm{\ρ}}_D\\ +R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}-{\mathrm{\τ}}_{l_3}-{\mathrm{\τ}}_{l_4}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_C{\mathrm{\ρ}}_D\\ +R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}-{\mathrm{\τ}}_{l_3}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_C{\mathrm{\ρ}}_E+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}-{\mathrm{\τ}}_{l_3}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_C{\mathrm{\ρ}}_F\\ +R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_A{\mathrm{\ρ}}_E+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}-{\mathrm{\τ}}_{l_5}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_B{\mathrm{\ρ}}_E\\ +R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_A{\mathrm{\ρ}}_F+R_x(\mathrm{\τ}-{\mathrm{\τ}}_{l_1}-{\mathrm{\τ}}_{l_2}-{\mathrm{\τ}}_{l_6}){\mathrm{\ρ}}_B{\mathrm{\ρ}}_F\end{array}$

In formula, R_x(τ) being auto-correlation function, τ is the optical path delay amount of two-arm light beam in light path correlator, and ρ is each solder joint Crosstalk coefficient, i.e. correspond to each peak in collection of illustrative plates, the corresponding different relevant peak of different optical path delay amounts, such as interference peaks position and Shown in amplitude table.

It addition, due to the characteristic of High Extinction Ratio polarizer (Y waveguide) self in the measurement assembly of quantitative crosstalk labelling, fill Dividing utilizes its single shaft to lead to light and the characteristic of extremely low crosstalk, can enter the light through High Extinction Ratio polarizer (Y waveguide) axle Row is effective to be filtered, and reduces the impact of unwanted noise, obtains steady and audible peak value collection of illustrative plates, it is thus achieved that high in measured zone Certainty of measurement.

For clearly demonstrating present invention OCDP based on high-order crosstalk white light caliberating device, in conjunction with the embodiments with accompanying drawing to the present invention It is described further, but should not limit the scope of the invention with this.

High Extinction Ratio polarizer measurement apparatus, as shown in Figure 4.Selection and the parameter thereof of main photoelectric device are as follows:

(1) centre wavelength 1550nm of adjustable wide spectrum light source 101, half spectral width are more than 45 ° of nm, fiber power bracket 0～2mW, extinction ratio is more than 6dB；

(2) 1 × 2 bonder 102 operation wavelengths are 1550nm, and extinction ratio is more than 20dB, and insertion loss is less than 0.5dB, point Light ratio is 2/98；

(3) operation wavelength of fibre optic isolater 104 is 1550nm, and extinction ratio is 30dB, and insertion loss is less than 1dB；

The operation wavelength of (4) 45 ° of polarizers 111 is 1550nm, and extinction ratio is 30dB, and insertion loss is less than 1dB, input End is single-mode fiber, is output as panda type polarization-preserving fiber；

The operation wavelength of (5) 45 ° of analyzers 116 is 1550nm, and extinction ratio is 30dB, and insertion loss is less than 1dB, input For panda type polarization-preserving fiber, outfan is single-mode fiber；

The operation wavelength of (6) 1 × 2 bonders 131 is 1550nm, and insertion loss is less than 0.5dB, and splitting ratio is 50/50；

(7) operation wavelength of polarization beat length device 132 is 1550nm, and insertion loss is 0.5dB；

(8) operation wavelength of light path scanning device 133 is 1550nm, and its light path scanning distance about becomes between 0～400mm Changing, average insertion loss is 3.0dB；

The operation wavelength of (9) 2 × 2 bonders 134 is 1550nm, and insertion loss is less than 0.5dB；

(10) light-sensitive material of detector 103,135,136 is InGaAs, and optical detection scope is 1100～1700nm, as Use the Nirvana of New Focus company^TMSeries 2017 type balanced detector.

(11) measurement wavelength 1260nm～1650nm of extinction ratio tester, polarization extinction ratio scope 0～50dB, precision ± 0.3dB.

The work process of polarizer measurement apparatus is as follows in high precision:

Embodiment 1: the High Extinction Ratio measuring method of a kind of optical fiber polarizer

(1) from Y waveguide 113 input y1 input beam, C point crosstalk PER is measured_cValue.

(2) from Y waveguide 113 outfan y2 input beam, D point crosstalk PER is measured_dValue.

(3) length at each section of polarization maintaining optical fibre measured in assembly of quantitative crosstalk labelling is chosen, and the guarantor of 45 ° of analyzers 116 is inclined Optical fiber ps2, polarization maintaining optical fibre 115, Y waveguide 113 export tail optical fiber y2, Y waveguide input tail optical fiber y1, polarization maintaining optical fibre 114,45 ° The polarization maintaining optical fibre ps1 of the polarizer 111 is respectively set as: l₁=0.6m, l₂=0.6m, l₃=0.1m, l₄=0.2m, l₅=0.3m, l₅=0.6m.

(4) Y waveguide 113 outfan y2 uses with polarization maintaining optical fibre 115 the inclined bonding machine of guarantor be directed at, and polarization maintaining optical fibre 115 exports Light beam extinction ratio tester is measured in real time, and the value of the extinction ratio now measured is PER_b+PER_c, rotational alignment angle, make PER_b Amount reaches setting value-30dB, now, is welded with polarization maintaining optical fibre 115 by Y waveguide 113 outfan y2, record value PER now_b。

(5) the outfan y2 of Y waveguide 113 use with polarization maintaining optical fibre 114 the inclined bonding machine of guarantor be directed at, from polarization maintaining optical fibre 114 Output beam extinction ratio tester is measured in real time, and the value of the extinction ratio now measured is PER_d+PER_e, rotational alignment angle, Make PER_eAmount reaches setting value-45dB, now, is welded with polarization maintaining optical fibre 114 by Y waveguide 113 input y1, records this Time value PER_e。

(6) the 45 ° of polarizer 111 polarization maintaining optical fibre ps1 and 114,45 ° of analyzers 111 of polarization maintaining optical fibre are protected inclined tail optical fiber ps2 with Equal 0 °～the 0 ° alignment welding of polarization maintaining optical fibre 115.

(7) connect wide spectrum light source to fill with signal record with power monitoring apparatus 100, light path correlator 120, polarization interference detection Put 130.

(8) wide spectrum light source 101, regulation polarization beat length device 132 and optical scanner 133 to interference signal maximum rating are opened. Drive light path scanning device 133, use polarization interference detection with signal recording apparatus 140 to different scanning in light path correlator 130 The data of distance measure and record, it is thus achieved that distributed polarization crosstalk measurement result, and the polarization crosstalk that record is measured in collection of illustrative plates is made an uproar The position of sound background data and each interference peaks and amplitude. (9) being normalized interference illustration data, comparison is in position and the height of the single order interference peaks interfering main peak both sides. τ it is in obtaining_l1、τ_l1+τ_l2、τ_l1+τ_l2+τ_l3、τ_l4+τ_l5+τ_l6、τ_l5+τ_l6、τ_l6ρ corresponding to position_A、ρ_B、ρ_C、ρ_D、ρ_E、 ρ_FThe amplitude at peak, and to PER_bWith ρ_B、PER_cWith ρ_C、PER_dWith ρ_D、PER_eWith ρ_EValue carry out demarcating and self calibration, Obtain the exact numerical at each single order crosstalk peak.

(10) obtain being in τ_l1+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l3+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l3+τ_l5+τ_l6、 τ_l1+τ_l2+τ_l3+τ_l6ρ corresponding to position_A+ρ_D、ρ_B+ρ_D、ρ_C+ρ_D、ρ_C+ρ_E、ρ_C+ρ_FThe size at peak, with the peak in collection of illustrative plates Position and amplitude compare, the exact numerical at available each second order crosstalk peak, for the demarcation in High Extinction Ratio region and from Calibration.

(10) by measuring at τ_l1+τ_l2+τ_l3+τ_l4+τ_l5+τ_l6+τ_lY(i.e. the outermost of interference illustration) place's peak amplitude, is treated Survey the exact numerical of the extinction ratio of Y waveguide, complete accurately to measure.

Claims (2)

1. a High Extinction Ratio measuring method for optical fiber polarizer, the i.e. Y waveguide of High Extinction Ratio polarizer to be measured input, Outfan is respectively welded the polarization maintaining optical fibre of two sections of different lengths, constitutes the measurement assembly with quantitative crosstalk labelling；Utilize during welding The extinction ratio of lump type extinction ratio tester butt welding contact carries out fixing quantity and records its measured value, simultaneously to polarizer tail optical fiber, Analyzer tail optical fiber, High Extinction Ratio polarizer tail optical fiber, the length of welding polarization maintaining optical fibre are set；Assembly will be measured and access distribution In formula optical fiber polarisation crosstalk test device, utilize the second order crosstalk measured value between external optical fiber pad that polarizer to be measured is disappeared Light ratio carries out demarcating and self calibration；It is characterized in that, comprise the steps:

(1) from Y waveguide (113) input (y1) input beam, lump type extinction ratio tester is utilized to measure C point crosstalk PER_cValue；

(2) length of Y waveguide (113) outfan (y2) is intercepted as l₃, the length of polarization maintaining optical fibre (115) is taken as l₂, Using and protect inclined bonding machine alignment, polarization maintaining optical fibre (115) output beam lump type extinction ratio tester is measured in real time, disappearing of measurement The value of light ratio is PER_b+PER_c；Rotational alignment angle, makes PER_bAmount reaches setting value, by Y waveguide (113) outfan (y2) Weld with polarization maintaining optical fibre (115), record value PER now_b；

(3) from polarization maintaining optical fibre (115) input beam, lump type extinction ratio tester is utilized to measure D point crosstalk PER_dValue；

(4) length of the input (y1) of Y waveguide (113) intercepts as l₄, the length of polarization maintaining optical fibre (114) is taken as l₅, Using and protect inclined bonding machine alignment, the output beam lump type extinction ratio tester of polarization maintaining optical fibre (114) is measured in real time, measurement The value of extinction ratio is PER_d+PER_e；Rotational alignment angle, makes PER_bAmount reaches setting value, by Y waveguide (113) input (y1) weld with polarization maintaining optical fibre (114), record value PER now_e。

(5) 45 ° of polarizers (111) are protected inclined tail optical fiber (ps1), 45 ° of analyzers (116) protect the length of inclined tail optical fiber (ps2) Degree intercepts as l₆, l₁, by 45 ° of polarizers (111) polarization maintaining optical fibre (ps1) and polarization maintaining optical fibre (114), 45 ° of analyzers (111) Protect inclined tail optical fiber (ps2) 0 °～0 ° alignment equal with polarization maintaining optical fibre (115) to weld；

(6) connect wide spectrum light source to remember with signal with power monitoring apparatus (100), light path correlator (130), polarization interference detection Recording device (140)；

(7) opening wide spectrum light source (101), regulation polarization beat length device (132) and optical scanner (133) are to interference signal Maximum rating, drives light path scanning device (133), uses polarization interference detection with signal recording apparatus (140) to light path correlator (130) in, the data of different scanning distance measure and record, it is thus achieved that distributed polarization crosstalk measurement result, and figure measured in record The position of the polarization crosstalk Noise Background data in spectrum and each interference peaks and amplitude；

(8) being normalized interference illustration data, comparison is in position and the height of the single order interference peaks interfering main peak both sides； Intercepted length l according to known fiber optic₁、l₂、l₃、l₄、l₅、l₆, utilize relational expression:

τ=Δ n_fl

τ it is in obtaining_l1、τ_l1+τ_l2、τ_l1+τ_l2+τ_l3、τ_l4+τ_l5+τ_l6、τ_l5+τ_l6、τ_l6ρ corresponding to position_A、ρ_B、ρ_C、ρ_D、 ρ_E、ρ_FThe amplitude at peak, and to PER_bWith ρ_B、PER_cWith ρ_C、PER_dWith ρ_D、PER_eWith ρ_EValue carry out demarcating and self-correcting Standard, obtains the exact numerical at each single order crosstalk peak；

Optical path delay amount is respectively 0,Crosstalk coefficient depend on Secondary be 1, ρ_A、ρ_B、ρ_C、ρ_D、ρ_E、ρ_F；

(9) on the basis of single order interference peaks, by calculating, obtain being in τ_l1+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l4+τ_l5+τ_l6、 τ_l1+τ_l2+τ_l3+τ_l4+τ_l5+τ_l6、τ_l1+τ_l2+τ_l3+τ_l5+τ_l6、τ_l1+τ_l2+τ_l3+τ_l6ρ corresponding to position_A+ρ_D、ρ_B+ρ_D、ρ_C+ρ_D、 ρ_C+ρ_E、ρ_C+ρ_FThe size at peak, compares with position and the amplitude at the peak in collection of illustrative plates, obtains the perfect number at each second order crosstalk peak Value, is used for the demarcation to High Extinction Ratio region and self calibration；Optical path delay amount is respectively Crosstalk Coefficient is followed successively by ρ_A+ρ_D、ρ_B+ρ_D、ρ_C+ρ_D、ρ_C+ρ_E、ρ_C+ρ_F；

(10) by measuring at τ_l1+τ_l2+τ_l3+τ_l4+τ_l5+τ_l6+τ_lYI.e. peak amplitude at the outermost of interference illustration, obtains Y to be measured The exact numerical of the extinction ratio of waveguide, completes accurately to measure, optical path delay amountCrosstalk system Number is ε_chip。

The High Extinction Ratio measuring method of a kind of optical fiber polarizer the most according to claim 1, it is characterised in that: described 45 ° of analyzers (116) protect inclined tail optical fiber (ps2), polarization maintaining optical fibre (115), Y waveguide (113) outfan (y2), Y waveguide (113) input (y1), polarization maintaining optical fibre (114), 45 ° of polarizers (111) protect length l of inclined tail optical fiber (ps1)₁、l₂、 l₃、l₄、l₅、l₆Choose, meet four square relations of plane:

1) ensure to make the single order of correspondence, second order interference peak in interference illustration be interspersed in interference illustration:

l₁≠l₆≠l₁+l₂≠l₅+l₆≠l₁+l₆

≠l₁+l₂+l₃≠l₁+l₂+l₆

≠l₁+l₅+l₆≠l₄+l₅+l₆

≠l₁+l₄+l₅+l₆≠l₁+l₂+l₃+l₆≠l₁+l₂+l₅+l₆；

≠l₁+l₂+l₄+l₅+l₆≠l₁+l₂+l₃+l₅+l₆

≠l₁+l₂+l₃+l₄+l₅+l₆

≠l₁+l₂+l₃+l₄+l₅+l₆+l_Y

2) input polarization maintaining optical fibre (y1) length L of Y waveguide (113)_inOptical path difference more than wide spectrum light source (101) ripple phase The light path L at dry peak_r, it may be assumed that L_in×Δn_f>L_r, L_inInclined tail optical fiber ps1 is protected for input tail optical fiber y1,114,45 ° of polarizers of polarization maintaining optical fibre Length sum, Δ n_fFor polarization maintaining optical fibre linear birefrigence；

3) output polarization maintaining optical fibre (y2) length L of Y waveguide (113)_outOptical path difference more than Y waveguide (113) speed own Optical path difference between axle, it may be assumed that L_out×Δn_f>L_Y×Δn_Y；L_outProtect for output tail optical fiber y2,115,45 ° of analyzers of polarization maintaining optical fibre Tail optical fiber ps2 length sum partially；L_YFor Y waveguide length, Δ n_YLinear birefrigence for Y waveguide；

4) the light path sweep limits Δ L measured

ΔL>2(L_in+L_Y+L_out)

The midpoint of light path sweep limits is the position of the peak-peak of polarization crosstalk measurement data.