CN103743553A - Double-channel optical performance testing device of integrated waveguide modulator and polarization crosstalk identification and processing method thereof - Google Patents

Abstract

The invention particularly relates to a double-channel optical performance testing device of an integrated waveguide modulator and a polarization crosstalk identification and processing method thereof and belongs to the technical field of measurement of optical devices. The double-channel optical performance testing device of the integrated waveguide modulator comprises a high-polarization stability wide spectrum light source, an integrated waveguide modulator to be detected, an optical distance demodulating device and a polarization crosstalk detecting and recording device. According to the device, the system structure is simplified and the testing function is enriched; the cost is reduced and the testing efficiency is improved; the double-channel optical performance testing device can be widely applied to a quantitative test of the optical performance of integrated waveguide devices with an extinction ratio greater than 80dB.

Description

A kind of binary channels optical performance test device of integrated waveguide modulator and polarization crosstalk identification and disposal route

Technical field

The present invention's design belongs to optical device field of measuring technique, is specifically related to a kind of binary channels optical performance test device and polarization crosstalk identification and disposal route of integrated waveguide modulator.

Background technology

Fiber optical gyroscope is commonly called as " Y waveguide ", the general lithium niobate material that adopts is as substrate, it has carried out monomode optical waveguide, beam splitter, photomodulator and optical polarizator highly integrated, be the core devices that forms interference optical fiber top (FOG) and optical fiber current mutual inductor, determining measuring accuracy, stability, volume and the cost of optical fiber sensing system.

The Important Parameters of Y waveguide device mainly comprises: waveguide chip extinction ratio, tail optical fiber cross-talk, output channel optical path difference, the temperature characterisitic of above-mentioned parameter etc.How to the optical property of Y waveguide device carry out accurately, comprehensively test is run in high performance device research and production one very stubborn problem.More than the chip extinction ratio of the Y waveguide using in high precision micron order optical fibre gyro requires to reach 80dB.For example, a kind of method (CN201310185490.2) that improves optical fibre gyro use Y waveguide chip extinction ratio that the Hua Yong of No.44 Inst., China Electronical Science and Technology Group Co., the equality people of relaxing propose, can realize the above Y waveguide device of 80dB.And conventional polarization property detecting instrument---extinction ratio tester, the Model4810 type polarization extinction ratio measuring instrument of the U.S. dBm Optics company development that resolution is the highest also only has 72dB; The High Extinction Ratio of the PEM-330 type of the ER2200 type of the ERM102 type of all the other U.S. General Photonics companies, Korea S Fiberpro company, Japanese Santec company all can only reach 50dB left and right.

Y waveguide device is comprised of several parts such as input optical fibre, waveguide chip and output optical fibre, modulator electrode etc., at least comprises an input channel and two output channels.The complicacy of structure requires except chip extinction ratio, and the linear birefrigence of remaining chip is penetrated, tail optical fiber cross-talk, Insertion Loss loss, output channel optical path difference, and the performance such as the temperature characterisitic of above-mentioned parameter, voltage characteristic is also the parameter that must measure.

Early 1990s, the people (US4893931) such as French Herve Lefevre disclose the OCDP system based on white light interference principle first, and it adopts super-radiance light emitting diode (SLD) and space interference light path to measure structure.France Photonetics company has developed WIN-P125 and two kinds of model OCDP test macros of WIN-P400 according to this patent, is mainly used in shorter (500m) and grows the polarization characteristic analysis of (1600m) polarization maintaining optical fibre.Its main performance is polarization crosstalk sensitivity for-70dB, dynamic range are 70dB, after through improvement, rise to respectively-80dB of sensitivity and dynamic range and 80dB.But the measurement for High Extinction Ratio Y waveguide is also slightly inadequate.

The people such as Alfred Healy of U.S. Fibersense Technology Corporation company in 2002 disclose a kind of coupling process (US6870628) of I/O optical fiber of integrated waveguide chip, utilize white light interferometry method to realize the measurement of the coupling cross-talk of waveguide chip I/O optical fiber; The people such as the Yi little Su of BJ University of Aeronautics & Astronautics in 2004, Xiao Wen disclose integrated optical modulator on-line testing method and proving installation (CN200410003424.X) thereof for a kind of optical fibre gyro, can realize the measurement of the optical parametrics such as loss, splitting ratio of device; The people such as the Yi little Su of BJ University of Aeronautics & Astronautics in 2007, Xu little Bin disclose a kind of Y waveguide chip and polarization maintaining optical fibre online to shaft device and online to axle method (CN200710064176.3), utilize interferometric spectrometry to realize equally the measurement of waveguide chip and waveguide I/O fiber crosswalk.But the measurement problem that does not relate to waveguide chip extinction ratio.

2011, the people such as the Zhang Hongxia of University Of Tianjin disclose a kind of detection method and pick-up unit (CN201110052231.3) of polarization extinction ratio of optical polarizer, the same space interference light path that adopts is as the core apparatus of OCDP, by detecting the stiffness of coupling of Coupling point, derive polarization extinction ratio.This device is applicable to the multiple optical polarization devices such as polarization maintaining optical fibre, polarization-maintaining fiber coupler, polarizer.Compare with the people's such as Herve Lefevre scheme, technical feature and index are close.

The same year, the people such as Yao Xiaotian of AM General photoelectricity company (General Photonics Corporation) disclose a kind of full optical measuring system (US20110277552 for polarization maintaining optical fibre and optical birefringence material distributed polarization crosstalk measurement, Measuring Distributed Polarization Crosstalk in Polarization Maintaining Fiber and Optical Birefringent Material), utilization increased optical path delay device before light path correlator, quantity and the amplitude of spuious white light interference signal while suppressing polarization crosstalk measurement.The method can be by the bring up to-95dB of polarization crosstalk sensitivity of full optical measuring system, but dynamic range remains on 75dB.

2012, this seminar has proposed the polarization crosstalk measurement proving installation (CN201210379406.6) based on full optical fiber optical optical road and has improved the method (CN201210379407.0) of optical device polarization crosstalk measurement performance, the technical scheme that adopts full optical fiber optical optical road and suppress to clap noise, greatly suppress noise amplitude, make that sensitivity that polarization crosstalk is measured improves-more than 95dB, dynamic range can correspondingly remain on 95dB simultaneously, the volume that has simultaneously reduced test macro, has increased Measurement sensibility.For the feature measurement of High Extinction Ratio Y waveguide device is laid a good foundation.

Traditional view is thought: the optical property of two output terminals of Y waveguide as chip extinction ratio, linear birefrigence be consistent.But the research of actual test shows: be limited to material and the manufacture craft of Y waveguide, the optical property of two output channels may have different, and this manufacture craft for Analysis of Waveguide and parameter have very large meaning; Y waveguide measuring system based on white light interferometric principle, only possesses single pass power of test, in the time of need to measuring two of Y waveguide output channels, must measure at twice; Particularly when external environment parameters (as temperature etc.) or application parameter (as the electrode on-load voltage of waveguide chip etc.) change, twice single channel measurement and a binary channels are measured simultaneously, when extraneous loading environment and Measuring Time there are differences, equivalence completely.Therefore, for the parameter of the different output channels of Y waveguide device, as: absolute value and the difference value of the optical characteristics such as waveguide chip extinction ratio, linear birefrigence, insertion loss, tail optical fiber cross-talk, have very great actual value.But proving installation does not also relate to full test and the assessment to the different output channel optical properties of Y waveguide device and otherness thereof with method at present.

The invention provides a kind of binary channels optical property while proving installation of Y waveguide device, its design philosophy is: based on full optical fiber optical optical line structure, the demodulated interferential instrument of two cover functional independences is respectively used to two output channels of Y waveguide device, utilize symmetry principle, by to the organic composite of proving installation structure and simplification, by the consistance of light path and device parameters is set, realized comprehensive measurement of the optical property parameter of Y waveguide device.The feature of device comprises two demodulated interferential instrument that functional independence, light channel structure and parameter are identical, they are connected to two output channels of waveguide modulator, and share same light path scanner, it is particularly suitable for loading under the environmental parameter load such as temperature, Y waveguide device output channel optical property is changed and the evaluate and analyze of inconsistency, when can realize the absolute value of the optical parameters such as waveguide chip extinction ratio between integrated waveguide device two output channels, linear birefrigence, insertion loss, tail optical fiber cross-talk and difference value, measure.Have that test parameter is comprehensive, measuring accuracy is high, good stability, the advantages such as light channel structure is simple, both reduce system cost, and improved again testing efficiency, saved testing cost, can be widely used in the quantitative test of the optical property of the above High Extinction Ratio integrated waveguide of 80dB device.

Summary of the invention

The object of the present invention is to provide a kind of binary channels optical performance test device of integrated waveguide modulator, the present invention also aims to provide a kind of polarization crosstalk identification and disposal route of binary channels optical performance test device of integrated waveguide modulator.

The object of the present invention is achieved like this:

A binary channels optical performance test device for integrated waveguide modulator, comprises that high polarization degree of stability wide spectrum light source, integrated waveguide modulator to be measured, light path demodulating equipment, polarization crosstalk detect and pen recorder:

The first output channel of integrated waveguide modulator to be measured and the second output channel are connected to the first demodulated interferential instrument and the second demodulated interferential instrument of light path demodulating equipment; Polarization crosstalk detects and is connected the first demodulated interferential instrument and the second demodulated interferential instrument with pen recorder simultaneously, and opto-electronic conversion and signal processing unit are processed and record the white light interference signal of the second differential detector output in the first differential detector in the first demodulated interferential instrument and the second (FBG) demodulator simultaneously; Control polarization crosstalk identification and disposal route that computing machine utilizes built-in integrated waveguide modulator to be measured, absolute value to the waveguide chip extinction ratio between the first output channel of integrated waveguide modulator to be measured and the second output channel, linear birefrigence, insertion loss, tail optical fiber cross-talk is measured, Storage & Display, and the performance difference when external environment parameters or application parameter change is compared and shown.

The first demodulated interferential instrument and the second demodulated interferential instrument: the first demodulated interferential instrument is connected with the first end of the one 2 * 2 fiber coupler by the first optical fiber analyzer, the second end of the one 2 * 2 fiber coupler is connected with the first end of the 22 * 2 fiber coupler, the 3rd end of the one 2 * 2 fiber coupler is connected by the first optical fiber circulator with the 4th end of the 22 * 2 fiber coupler, the 4th end of the one 2 * 2 fiber coupler is connected with a DFB light source, the other end of the first optical fiber circulator connects the first fiber collimating lenses, the second end of the 22 * 2 fiber coupler is connected the first differential detector with the 3rd end,

The second demodulated interferential instrument is identical with the composition of the first demodulated interferential instrument, consists of respectively the second optical fiber analyzer, the 32 * 2 fiber coupler, the 42 * 2 fiber coupler, the second optical fiber circulator, the second fiber collimating lenses, the second differential detector, the 2nd DFB light source.

High polarization degree of stability wide spectrum light source, the first output terminal by fiber coupler is connected in the first photodetector; By the second output terminal, after fibre optic isolater, be connected in the optical fiber polarizer.

The annexation of integrated waveguide modulator to be measured and high polarization degree of stability wide spectrum light source and light path demodulating equipment is:

It is 0～45 ° to shaft angle degree that inclined to one side tail optical fiber is protected in the input of the output polarization maintaining optical fibre of the optical fiber polarizer and integrated waveguide modulator input channel to be measured;

What inclined to one side tail optical fiber and the first optical fiber analyzer of the first demodulated interferential instrument and the second demodulated interferential instrument were protected in the first output channel of integrated waveguide modulator to be measured, the output of the second output channel, inclined to one side tail optical fiber is protected in the input of the second optical fiber analyzer is respectively 0～45 ° to shaft angle degree.

A kind of polarization crosstalk identification and disposal route of binary channels optical performance test device of integrated waveguide modulator:

1) detect the length l that inclined to one side tail optical fiber is protected in input _w-,, judge whether to meet:

S _W-i=l _W-i×Δn _f>S _ripple

In formula: Δ n _ffor protecting inclined to one side tail optical fiber linear birefrigence, S _ripplelight path maximal value for light source Secondary coherence peak;

2) if do not met, weld an elongated segment polarization maintaining optical fibre l _f-i, to shaft angle degree, be 0 °-0 °, measure and record extended fiber l _f-ilength and theoretical light path S _f-i, judgement:

S _f-i=l _f-i×Δn _f>S _ripple

3) measure the length l of waveguide chip _w;

4) measure the length l of the first output channel tail optical fiber, the second output channel tail optical fiber _w-o-1, l _w-o-2, judgement:

S _w-o-1=l _w-o-1* Δ n _fand S _w-o-2=l _w-o-1* Δ n _f>S _w=l _w* Δ n _w

In formula: Δ n _wthe linear birefrigence of waveguide chip;

5) as the length l of output channel tail optical fiber _w-o-1, l _w-o-2do not meet the condition of step 4), in the first output channel, the second output channel, weld respectively the extended fiber l that two segment length are identical _f-o-1, l _f-o-2, it is 0 °-0 ° to shaft angle degree, its length requirement meets:

S _f-o-1=l _f-o-1* Δ n _fand S _f-o-2=l _f-o-1* Δ n _f>S _w=l _w* Δ n _w, measure and record extended fiber l _f-o-1, l _f-o-2;

6) integrated waveguide modulator to be measured is connected with light path demodulating equipment with wide spectrum light source, its input and and output shaft angle degree is respectively to θ ₁=45 °, θ ₂=45 °;

7) start white light interferometer, obtain two width distributed polarization crosstalk measurement result curve of the first output channel, the second output channel simultaneously;

8) utilize the geometrical length of the device each several part of having measured, comprising: inclined to one side tail optical fiber length l is protected in input _w-i, input extends polarization maintaining optical fibre length l _f-i, waveguide chip length l _w, the first output channel, the second output channel tail optical fiber length l _w-o-1, l _w-o-2, output extended fiber length l _f-o-1, l _f-o-2; Calculate its optical path delay amount, and according to size, to be arranged in order be two row:

The corresponding first wave guide output channel of the first row: S _f-i, (S _f-i+ S _w-i), S _f-o-1, (S _f-o-1+ S _w-o-1), (S _f-o-1+ S _w-o-1+ S _f-i+ S _w-i+ S _w-1)

Corresponding the second waveguide output channel: the S of the second row _f-i, (S _f-i+ S _w-i), S _f-o-2, (S _f-o-2+ S _w-o-2), (S _f-o-2+ S _w-o-2+ S _f-i+ S _w-i+ S _w-2)

9) contrast with theoretical formula, determine the polarization crosstalk characteristic peak that the first output channel is measured, be specially:

(1) the polarization crosstalk ρ of waveguide input extended fiber and waveguide input tail optical fiber _f-i;

(2) the polarization crosstalk ρ of waveguide input tail optical fiber and waveguide chip _w-i;

(3) the polarization crosstalk ρ of output extended fiber and the first output channel waveguide output tail optical fiber _f-o-1;

The polarization crosstalk ρ of (4) first output channel waveguide output tail optical fibers and waveguide chip _w-o-1;

(5) polarization crosstalk of the Y waveguide chip that first passage is measured

Determine the polarization crosstalk characteristic peak that the second output channel (2C) is measured, be specially:

(1) the polarization crosstalk ρ of waveguide input extended fiber and waveguide input tail optical fiber (21) _f-i;

(2) the polarization crosstalk ρ of waveguide input tail optical fiber (21) and waveguide chip (2D) _w-i;

(3) the polarization crosstalk ρ of output extended fiber and the second output channel waveguide output tail optical fiber _f-o-2;

The polarization crosstalk ρ of (4) second output channel waveguide output tail optical fibers and waveguide chip (2D) _w-o-2;

(5) polarization crosstalk of the Y waveguide chip that second channel is measured

10) contrast polarization crosstalk

with polarization crosstalk

polarization crosstalk ρ _w-o-2with polarization crosstalk ρ _w-o-1;

11) according to the birefringence n of the polarization maintaining fiber pigtail calculating and waveguide chip actual measurement _f, Δ n _w; I (0) _out1/ I (0) _out2represent the insertion loss ratio that first, second output channel of waveguide device is measured;

12) when external environment parameters or application parameter variation, re-execute step 7), optical parametric to Y waveguide is measured, and the parameter that can measure also comprises the changes in optical properties of two output channels, comprises the coupling cross-talk variation with temperature of I/O optical fiber and waveguide chip; The chip extinction ratio of waveguide two output channels is with the variation of impressed voltage.

Beneficial effect of the present invention is:

(1) as a kind of comprehensive proving installation of Y waveguide device optical property, the optical parametric that can measure is maximum, also the most comprehensive, comprise waveguide chip extinction ratio, linear birefrigence, tail optical fiber cross-talk, insertion loss between Y waveguide device two output channels, and the conforming measurement of output channel, single pass can obtain the measurement of numerous parameters, and testing efficiency is high, good stability, affected by environment little;

(2) adopt completely independently two cover demodulated interferential instrument of function, can measure the optical characteristics of two output channels simultaneously, can realize different waveguide output channel when environmental parameter (as temperature etc.) or application parameter (as the electrode on-load voltage of waveguide chip etc.) load, the optical property variation of Y waveguide device and the evaluate and analyze of inconsistency thereof, both improve testing efficiency, saved again testing cost;

(3) full same light path design (comprising light channel structure and component parameters), shares same light path scanner, has reduced system constructing cost, has improved test speed, has reduced the measurement inconsistency between passage;

(4) adopt full optical fiber optical optical road, have that volume is little, measuring accuracy is high, temperature stability and an anti-vibration good stability etc.

Accompanying drawing explanation

Fig. 1 is the optical principle schematic diagram of the distributed polarization crosstalk measurement of optical device;

Fig. 2 is interference signal amplitude and the light path corresponding relation schematic diagram that polarization crosstalk forms;

Fig. 3 is the Y waveguide device binary channels optical performance test schematic diagram of device based on Mach-Zehnder demodulated interferential instrument;

Fig. 5 is that waveguide tail optical fiber slow axis is aimed at the fast axle of waveguide chip, during 0 °～0 ° of access proving installation of device, and the cloth formula polarization crosstalk data (the polarization interference noise of measurement mechanism) that measure;

Fig. 6 is 0 °～45 ° of the input, output of Y waveguide device during 45 °～0 ° of access measurement mechanism, the distributed polarization cross-talk data (optical characteristics of Y waveguide device) that measure from the first output channel 2B;

When Fig. 7 is 90 ° of Y waveguide devices～0 ° of access proving installation, the cloth formula polarization crosstalk data (the polarization interference noise of measurement mechanism) that measure from the first output channel 2C;

Fig. 8 is the power coupling cross-talk variation with temperature of Y waveguide input tail optical fiber and waveguide chip;

Fig. 9 is the power coupling cross-talk variation with temperature of Y waveguide the first output channel tail optical fiber and waveguide chip;

Figure 10 is the power coupling cross-talk variation with temperature of Y waveguide the second output channel tail optical fiber and waveguide chip;

Figure 11 is the measurement data summary sheet of Y waveguide the first output channel 2B;

Figure 12 is the measurement data summary sheet of Y waveguide the second output channel 2C;

Figure 13 is the linear birefrigence of the measurement of Y waveguide the first output channel 2B;

Figure 14 is the linear birefrigence of Y waveguide the second output channel 2C.

Embodiment

The binary channels optical property of a kind of Y waveguide device that the present invention proposes is proving installation simultaneously, comprise that high polarization degree of stability wide spectrum light source 1, integrated waveguide modulator to be measured (Y waveguide) 2, light path demodulating equipment 3, polarization crosstalk detect and pen recorder 4, is characterized in that:

1) first, second demodulated interferential instrument 31,32 that the first and second output channel 2B of Y waveguide 2,2C are connected to light path demodulating equipment 3;

2) light channel structure, element and the device parameters thereof of the first demodulated interferential instrument 31 and the second demodulated interferential instrument 32 are all identical, comprise 32 liang of arm optical path differences of the first interferometer 31 and the second interferometer and are connected optical fiber 300,320,302,322,304,324;

3) fiber collimating lenses 306 in the first demodulated interferential instrument 31 and the fiber collimating lenses in the second demodulated interferential instrument 32 326 share same light path scanner 310;

4) polarization crosstalk detects and is connected first, second demodulated interferential instrument 31,32 with pen recorder 4 simultaneously, opto-electronic conversion and signal processing unit 41, to first, second differential detector 308 and 309,328 and 329 output white light interference signals, are processed and record simultaneously;

5) control computing machine 42 and utilize data identification and Processing Algorithm, except the optical property of Y waveguide 2 first, second output channel 2B, 2C is measured, Storage & Display, also different in nature to the poor performance of output channel 2B, 2C, the performance particularly loading under the application conditions such as the environmental baselines such as temperature and voltage compares and shows.

First, second described demodulated interferential instrument 31,32, is characterized in that:

1) the first demodulated interferential instrument 31 is comprised of the first optical fiber analyzer the 301, the one 2 * 2 fiber coupler the 303, the 22 * 2 fiber coupler 307, the first optical fiber circulator 305, the first fiber collimating lenses 306, the first differential detector 308,309, a DFB light source 311 respectively;

2) the second demodulated interferential instrument 32 is comprised of the second optical fiber analyzer the 321, the 32 * 2 fiber coupler the 323, the 42 * 2 fiber coupler 327, the second optical fiber circulator 325, the second fiber collimating lenses 326, the second differential detector 328,329, the 2nd DFB light source 331 respectively;

3) light channel structure, element and the device parameters thereof of the first demodulated interferential instrument 31 and the second demodulated interferential instrument 32 are all identical, comprise 32 liang of arm optical path differences of the first interferometer 31 and the second interferometer size and are connected optical fiber 300 and 320,302 and 322,304 and 324 length;

Described high polarization degree of stability wide spectrum light source 1, is characterized in that: wide spectrum light source 11 is connected in the first photodetector 14 by the first output terminal 13 of fiber coupler 12; By the second output terminal 15, after fibre optic isolater 16, be connected in the optical fiber polarizer 17.

Described Y waveguide 2 and the annexation of high polarization degree of stability wide spectrum light source 1 and light path demodulating equipment 3, is characterized in that:

1) to protect 21 pairs of shaft angle degree of inclined to one side tail optical fiber be 0～45 ° for the output polarization maintaining optical fibre 18 of the polarizer 17 and the input of Y waveguide 2 input channel 2A;

2) what inclined to one side tail optical fiber 300,320 was protected in the input that first, second optical fiber analyzer 301,321 of inclined to one side tail optical fiber 22,23 and first, second demodulated interferential instrument 31,32 is protected in the output of first, second output channel 2B, the 2C of Y waveguide is respectively 0～45 ° to shaft angle degree.

The optical parameter measurement method of described Y waveguide 2 devices, is characterized in that:

1) length l of inclined to one side tail optical fiber 21 is protected in input _w-ibe required to meet following formula:

S _W-i=l _W-i×Δn _f>S _ripple （1）

In formula: Δ n _{f is}protect inclined to one side tail optical fiber linear birefrigence, S _ripplelight path maximal value for light source 11 Secondary coherence peaks.

2) if do not met, weld an elongated segment polarization maintaining optical fibre l _f-i, to shaft angle degree, be 0 °-0 °, length requirement similar (1) formula, meets (2) formula, measures and record extended fiber l _f-ilength and theoretical light path S _f-i;

S _f-i=l _f-i×Δn _f>S _ripple （2）

3) measure the length l of waveguide chip 2D _w;

4) measure the length l of first, second output channel tail optical fiber 21,22 of waveguide _w-o-1, l _w-o-2, its length requirement similar (1) formula, meets (3) formula:

S _w-o-1=l _w-o-1* Δ n _fand S _w-o-2=l _w-o-1* Δ n _f>S _w=l _w* Δ n _w(3)

In formula: Δ n _wthe linear birefrigence of waveguide chip.

5) as the length l of output tail optical fiber 21,22 _w-o-1, l _w-o-2do not meet (3) formula, in the one the second output channels, weld respectively the extended fiber l that two segment length are identical _f-o-1, l _f-o-2, it is 0 °-0 ° to shaft angle degree, its length requirement similar (3) formula meets (4) formula, measures and record extended fiber l _f-o-1, l _f-o-2;

S _f-o-1=l _f-o-1* Δ n _fand S _f-o-2=l _f-o-1* Δ n _f>S _w=l _w* Δ n _w(4)

6) Y waveguide 2 is connected with light path demodulating equipment 3 with light source 1, its input and and output shaft angle degree is respectively to θ ₁=45 °, θ ₂=45 °;

7) start white light interferometer, obtain the two width distributed polarization crosstalk measurement result curve of first, second output channel 2B, 2C simultaneously;

8) utilize the geometrical length of the device each several part of having measured, comprising: inclined to one side tail optical fiber 21 length l are protected in input _w-i, input extends polarization maintaining optical fibre length l _f-i, waveguide chip 2D length l _w, first, second output channel tail optical fiber 21,22 length l of waveguide _w-o-1, l _w-o-2, output extended fiber length l _f-o-1, l _f-o-2; Calculate its optical path delay amount, and according to its size, to be arranged in order be two row:

The first row (corresponding first wave guide output channel): S _f-i, (S _f-i+ S _w-i), S _f-o-1, (S _f-o-1+ S _w-o-1), (S _f-o-1+ S _w-o-1+ S _f-i+ S _w-i+ S _w-1)

The second row (corresponding the second waveguide output channel): S _f-i, (S _f-i+ S _w-i), S _f-o-2, (S _f-o-2+ S _w-o-2), (S _f-o-2+ S _w-o-2+ S _f-i+ S _w-i+ S _w-2)

9) follow with theoretical analysis result formula (7) and contrast, the scope that may occur according to optical path delay amount, determine and comprise the implication of each polarization crosstalk peak value:

Determine the polarization crosstalk characteristic peak that the first output channel 2B measures, be specially:

(1) the polarization crosstalk ρ of waveguide input extended fiber and waveguide input tail optical fiber 21 _f-i;

(2) the polarization crosstalk ρ of waveguide input tail optical fiber 21 and waveguide chip 2D _w-i;

(3) the polarization crosstalk ρ of output extended fiber and the first output channel waveguide output tail optical fiber 22 _f-o-1;

The polarization crosstalk ρ of (4) first output channel waveguide output tail optical fibers and waveguide chip 2D _w-o-1;

(5) polarization crosstalk of the Y waveguide chip that first passage is measured

Determine the polarization crosstalk characteristic peak that the second output channel 2C measures, be specially:

(1) the polarization crosstalk ρ of waveguide input extended fiber and waveguide input tail optical fiber 21 _f-i;

(2) the polarization crosstalk ρ of waveguide input tail optical fiber 21 and waveguide chip 2D _w-i;

(3) the polarization crosstalk ρ of output extended fiber and the second output channel waveguide output tail optical fiber 23 _f-o-2;

The polarization crosstalk ρ of (4) second output channel waveguide output tail optical fibers and waveguide chip 2D _w-o-2;

(5) polarization crosstalk of the Y waveguide chip that second channel is measured

10) contrast

with

ρ _w-o-2with ρ _w-o-1, inconsistent between known Y waveguide 2 two output channel 2B, 2C in performance;

11) according to formula (7) and (8), can calculate the birefringence n of polarization maintaining fiber pigtail and waveguide chip actual measurement _f, Δ n _w; I (0) _out1/ I (0) _out2represent the insertion loss ratio that first, second output channel of waveguide device is measured;

12) when external environment parameters (as temperature etc.) or application parameter (as the electrode on-load voltage of waveguide chip etc.) change, come back to step 7), again the optical parametric of Y waveguide is measured, the parameter that can measure except above-mentioned steps provide, also comprise the changes in optical properties of two passages:

(1) the coupling cross-talk variation with temperature of I/O optical fiber and waveguide chip;

(2) the chip extinction ratio of waveguide two output channels is with the variation of impressed voltage.

The present invention is a kind of technological improvement to the optical coherence territory polarization test system (OCDP) based on white light interference principle.As shown in Figure 1, the pad cross-talk performance test of polarization maintaining optical fibre of take is example to the principle of work of OCDP, and the high stable wide range polarized light 501 being sent by wide spectrum light source is injected into the slow axis (during fast axle, principle is identical) of the polarization maintaining optical fibre 521 of certain length.When transmission light passes through the pad 511 in optical fiber 521, in slow axis, a part of luminous energy of flashlight will be coupled in the fast axle of quadrature, forms coupled light beam 503, and remaining transmitting beam 502 is still transmitted along slow axis.When transmission light is during from the other one end outgoing of optical fiber 521 (transmission range is l), the linear birefrigence Δ n(existing due to optical fiber for example: 5 * 10 ^-4), make will have an optical path difference Δ nl between transmission light 502 in slow axis and the coupling light 503 in fast axle.Light beam 502 and 503 passes through pad or the connector 512 of 45 ° of rotations, and after the polarization polarization of analyzer 531, by optical splitter 532, is divided into equably respectively two parts.As shown in Figure 2, by transmission light 601 and coupling light 602, form reference beam, transmission, in the fixed arm of interferometer, is got back to optical splitter 532 after the reflection of stationary mirror 533; By transmission light 603 and coupling light 604, form scanning light beam, also get back to optical splitter 532 equally after the reflection of mobile mirror 534, two parts light converges on detector 537 and forms white light interference signal, is received and light signal is converted to electric signal.This signal, after signal demodulating circuit 551 is processed, is sent in metering computer 552; Metering computer 552 also will be responsible in addition controlling mobile mirror 534 and realize light path scanning.

As illustrated in fig. 1 and 2, under the control of metering computer 552, the optical path difference that the mobile mirror 534 of Michelson interferometer makes interferometer two arms from Δ nl through zero passage, be scanned up to-Δ nl:

(1) when optical path difference equals Δ nl, in scanning light beam, coupling light 604 is mated with transmission light 601 light paths in reference beam, produces white light interference signal, and its peak amplitude is

it is directly proportional to coupling amplitude factor and the intensity of light source of defect point;

(2) when optical path difference is zero, reference beam 601,602 mates with transmission light 605, coupling light 606 light paths in scanning light beam respectively, produces respectively white light interference signal, the intensity stack that its peak amplitude is the two, and its amplitude is I _main∝ I ₀, it is directly proportional to light source power input.As shown in Figure 2, compare with previous white light interference signal, the optical path difference between two white light interference signal peaks is just Δ nl.If the linear birefrigence Δ n of known optics, can calculate the position l that defect point occurs, and ratio by interference signal peak strength can calculate the power of the defect point big or small ρ that is coupled;

(3) when equal-Δ of optical path difference nl, in scanning light beam, transmission light 607 mates with coupling light 602 light paths in reference beam, produces white light interference signal, and its peak amplitude is it is identical when it is Δ nl with optical path difference.As figure shows, while being Δ nl with optical path difference, compare, this white light interference signal is symmetrical on light path with it, identical in amplitude.

Polarization crosstalk ρ can according to optical path difference be Δ nl or-polarization crosstalk signal amplitude I that Δ nl obtains _coupling, and optical path difference obtains transmitting optical signal amplitude I while being zero _maincalculate:

$\frac{I_{\mathrm{coupling}}}{I_{\mathrm{main}}}=\sqrt{\mathrm{\ρ}(1-\mathrm{\ρ})}---\left(5\right)$

Because general polarization crosstalk is much smaller than 1, therefore (1) formula is changed to:

$\frac{I_{\mathrm{coupling}}}{I_{\mathrm{main}}}=\sqrt{\mathrm{\ρ}}---\left(6\right)$

In order to obtain the optical characteristics of two output channels of Y waveguide device simultaneously, its proving installation as shown in Figure 3.When the alignment angle of Y waveguide device 2 and wide spectrum light source 1 and light path demodulating equipment 3 be 0 °～45 °, 45 °～0 ° on time, polarization crosstalk detects amplitude and the optical path delay amount of the white light interference signal of the first and second output channel 2B, the 2C that obtain with pen recorder 4, all meets (3) formula and represents:

$\left\{\begin{array}{c}\frac{I{\left(S_{\mathrm{out}1}\right)}_{\mathrm{out}1}}{I{\left(0\right)}_{\mathrm{out}1}}=R\left(S_{\mathrm{out}1}\right)+\sqrt{{\mathrm{\ρ}}_{f-i}}R(S_{\mathrm{out}1}\±S_{f-i})+\sqrt{{\mathrm{\ρ}}_{W-i}}R[S_{\mathrm{out}1}\±(S_{f-i}+S_{W-i})]\\ +\sqrt{{\mathrm{\ρ}}_{f-o-1}}R(S_{\mathrm{out}1}\±S_{f-o-1})+\sqrt{{\mathrm{\ρ}}_{W-o-1}}R[S_{\mathrm{out}1}\±(S_{f-o-1}+S_{W-o-1})]\\ +{\mathrm{\ϵ}}_{\mathrm{chip}1}R[S_{\mathrm{out}1}\±(S_{f-i}+S_{W-i}+S_{f-o-1}+S_{W-o-1}+S_{W-1})\\ \frac{I\left(S_{\mathrm{out}2}\right)}{I{\left(0\right)}_{\mathrm{out}2}}=R\left(S_{\mathrm{out}2}\right)+\sqrt{{\mathrm{\ρ}}_{f-i}}R(S_{\mathrm{out}2}\±S_{f-i})+\sqrt{{\mathrm{\ρ}}_{W-i}}R[S_{\mathrm{out}2}\±(S_{f-i}+S_{W-i-2})]\\ +\sqrt{{\mathrm{\ρ}}_{f-o}}R(S_{\mathrm{out}2}\±S_{f-o-2})+\sqrt{{\mathrm{\ρ}}_{W-o}}R[S_{\mathrm{out}2}\±(S_{f-o-2}+S_{W-o-2})]\\ +{\mathrm{\ϵ}}_{\mathrm{chip}2}R[S_{\mathrm{out}2}\±(S_{f-i}+S_{W-i-2}+S_{f-o-2}+S_{W-o-2}+S_{W2})\end{array}\right.---\left(7\right)$

In formula: I (S _out1), I (S _out2) be expressed as all white light interference signal amplitude sums that the first differential detector (308,309) and the second differential detector (328,329) are surveyed; S _out1, S _out2represent respectively the light path delayed sweep amount of first, second demodulated interferential instrument 31,32, I (0) _out1, I (0) _out2when optical path difference is zero respectively, represent the maximum peak amplitude of white light interference signal; The normalization self-coherence function that R (S) is wide spectrum light source, R (0)=1, the white light interference peak signal amplitude of transmission light, optical path difference is zero; R (S)=0(S>S ₀time, S ₀coherent length for wide spectrum light source); S _f-i, S _f-o-1, S _f-o-2, S _w-i, S _w-o-1, S _w-o-2, S _w-1, S _w-2be respectively input extended fiber, the first output channel extended fiber, the second output channel extended fiber, waveguide input tail optical fiber, waveguide the first output channel tail optical fiber, waveguide the second output channel tail optical fiber, the first output channel waveguide light path, the corresponding optical path delay amount of the second output channel waveguide light path, when slow axis light path is ahead of fast axial light journey, above-mentioned retardation is defined as+; When slow axis light path lags behind fast axial light journey, above-mentioned retardation is defined as-, each optical path delay amount can be expressed as successively:

S _f-i＝l _f-i×Δn _f

S _W-i＝l _W-i×Δn _f

S _f-o-1＝l _f-o-1×Δn _f

S _f-o-2＝l _f-o-2×Δn _f （8）

S _W-o-1＝l _W-o-1×Δn _f

S _W-o-2＝l _W-o-2×Δn _f

S _W-1＝l _W-1×Δn _W

S _W-2＝l _W-2×Δn _W

In formula, l _f-i, l _f-o-1, l _f-o-2, l _w-i, l _w-o-1, l _w-o-2, l _w-1, l _w-2be respectively the length of input extended fiber, the first output channel extended fiber, the second output channel extended fiber, waveguide input tail optical fiber, waveguide the first output channel tail optical fiber, waveguide the second output channel tail optical fiber, the first output channel waveguide chip, the second output channel waveguide chip, Δ n _f, Δ n _wbe respectively the linear birefrigence of polarization maintaining optical fibre and waveguide chip; ρ _f-i, ρ _f-o-1, ρ _f-o-2be respectively extended fiber and waveguide output tail optical fiber, the extended fiber of the second output channel and the solder joint polarization crosstalk power factor of waveguide output tail optical fiber of waveguide input extended fiber and waveguide input tail optical fiber, the first output channel, ρ _w-i, ρ _w-o-1, ρ _w-o-2be respectively the polarization crosstalk power factor of waveguide input, the first output tail optical fiber, the second output tail optical fiber and waveguide chip,

be respectively the Y waveguide chip polarization crosstalk (inverse of extinction ratio) of first, second channel measurement.

From (7), (8) formula, if known input, the first output, the second output extended fiber, the length of input, the first output, the second output waveguide tail optical fiber and waveguide chip, light path scanning by light path demodulating equipment 3 and polarization crosstalk detects and collection and the processing of the white light interference signal amplitude of pen recorder 4, is 0 in optical path delay amount, ± S _f-i, ± S _f-o-1, ± S _f-o-2, ± (S _f-i+ S _w-i), ± (S _f-o-1+ S _w-o-1), ± (S _f-o-2+ S _w-o-2), ± (S _f-o-1+ S _w-o-1+ S _f-i+ S _w-i+ S _w-1), ± (S _f-o-2+ S _w-o-2+ S _f-i+ S _w-i+ S _w-2) locate, can obtain respectively the peak value of white light interference signal, its amplitude is corresponding ρ respectively _f-i, ρ _f-o-1, ρ _f-o-2, ρ _w-i, ρ _w-o-1, ρ _w-o-2, deng optical parametric.

For integrated waveguide modulator of the present invention (Y waveguide) the simultaneously-measured device of dual output passage and measuring method are clearly described, the invention will be further described with accompanying drawing in conjunction with the embodiments, but should not limit the scope of the invention with this.

Embodiment 1---the waveguide measuring device based on Mach-Zehnder demodulated interferential instrument

Device measurement mechanism as shown in Figure 3, select with parameter as follows by the device of white light interferometric device:

(1) the centre wavelength 1550nm of wideband light source 11, half spectral width are greater than 45nm, and fiber power is greater than 2mW, be approximately-60dB of light source light spectrum ripple <0.05dB(peak amplitude), the light path scope 4～7mm at relevant peak; Half spectral width of DFB light source 311 is less than 50MHz, and fiber power is greater than 1mW;

(2) 2/98 fiber coupler 12 operation wavelength 1550nm, splitting ratio 2:98;

(3) fibre optic isolater 16 operation wavelength 1550nm, insertion loss 0.8dB, isolation >35dB;

(4) the optical fiber polarizer 17, and the operation wavelength of first, second optical fiber analyzer 301,321 is 1550nm, and extinction ratio is 30dB, and insertion loss is less than 1dB;

The parameter of (5) first, second, third, fourth fiber couplers 303,307,323,337 is identical, and operation wavelength is 1310/1550nm, splitting ratio 50:50;

(6) first, second fiber optical circulator 305,325 is three-port circulator, insertion loss 1dB, and return loss is greater than 55dB;

(7) operation wavelength of first, second collimation lens 306,326 is 1550nm, it and light path scanner 310(reflectivity are more than 92%) between light path scanning distance between 0～200mm, change greatly, average insertion loss is 2.0dB, in loss fluctuation ± 0.2dB, and light path scanner 310 is approximately when 100mm position, and two arm optical path differences of first, second demodulated interferential instrument 31,32 are approximately zero;

(8) first, second differential detector 308 and 309,328 and 329 photochromics are InGaAs, and photodetection scope is 1100～1700nm, and responsiveness is greater than 0.85;

(9) select Y waveguide device 2 to be measured, its operation wavelength is 1550nm, and waveguide tail optical fiber slow axis is aimed at the fast axle of waveguide chip, waveguide chip length 20mm.

The course of work of measurement mechanism is as follows:

The output light of wide spectrum light source 11 becomes line polarisation after the polarization of the light splitting of fiber coupler 12, the isolation of fibre optic isolater 16 and the polarizer 17, through protecting the guarantor of inclined to one side output optical fibre 18 and Y waveguide 2, partially input 45 ° of tail optical fiber 21 to axle solder joint again, luminous energy is injected in the fast and slow axis of waveguide chip 2D to be measured equably; First light signal is divided into two bundles, transmit respectively in 2B and 2C, existence due to the extinction ratio of Y waveguide, in waveguide slow axis, signal transmission light obtains compared with high attenuation, and fast axle transmission light slightly decay (corresponding insertion loss), fast and slow axis transmission light is together exported from the first output channel 2B of Y waveguide and the first output channel 2C, inject tail optical fiber 22 and 23, pass through respectively 45 ° of solder joints of tail optical fiber 300 and 320, in the first analyzer 301 and the second analyzer 321, mix respectively, and be injected into respectively in the first demodulated interferential instrument 31 and the second demodulated interferential instrument 32.

The first demodulated interferential instrument 31 of take is example, the flashlight of the flashlight of exporting from the slow axis of Y waveguide 2 and fast axle output is evenly divided into 2 bundles by 303, in the fixed arm that a branch of transmission forms at optical fiber 304, a branch of transmission is in the scan arm being comprised of the first circulator 305, first collimator 306 and light path scanner 310 in addition.When 310 motions of light path scanner realize light path scanning, when the optical path difference producing between the fixed arm of the first demodulated interferential instrument 31 and scan arm and Y waveguide 2 are fast, the optical path difference of slow axis output light matches, the first differential detector 308 and 309 will be exported white light interference signal, white light interference peak value and waveguide chip extinction ratio are inversely proportional to, the length of the corresponding waveguide chip of light path scanning position that its peak value is corresponding.Above-mentioned measuring process has obtained the optical property of the Y waveguide 2 of measuring from the first output channel.

The second demodulated interferential instrument 32 and the first demodulated interferential instrument share same light path scanner 310.Therefore,, when 310 work of light path scanner, the second demodulated interferential instrument 32 has almost obtained the optical property of the Y waveguide 2 of measuring from the first output channel simultaneously.

Embodiment 2---and the binary channels of the Y waveguide device of the fast axle of tail optical fiber slow axis and waveguide chip is measured simultaneously

As shown in Figure 3, optical property measurement procedure as shown in Figure 4 for the measurement mechanism figure of Y waveguide device.

(1), from step 701, measure Y waveguide input tail optical fiber length l _w-iit is 1.53 meters;

(2) from step 702, input tail optical fiber l _w-itheoretical light path (Δ n _fby 5 * 10 ^-4meter) S _w-i=0.765mm; And S _ripple=4～7mm, visible, must weld input extended fiber;

(3) known according to step 703, connect extended fiber l _f-ilength at least want 7 * 10 ^-3/ 5 * 10 ^-4=14 meters, actually choose 15 meters;

(4) known according to step 704, the length of measuring waveguide chip is 20mm, and (Δ nW is by 8 * 10 for its theoretical light path ^-2meter) S _w-o=1.6mm, corresponding output tail optical fiber length l _w-o=1.6 * 10 ^-3/ 5 * 10 ^-4=3.2 meters;

(5) known according to step 705, measure the tail optical fiber length l of first, second output channel _w-o-1, l _w-o-1it is 1.72 meters, 1.78 meters;

(6) known according to step 706～707, the light path S of output tail optical fiber _w-o-1, S _w-o-1all be less than S _w, visible, must extend output optical fibre, welding extended fiber l _f-oat least want 3.2 meters, actually choose 5.6 meters;

(7) owing to being to measure first, by Y waveguide I/O tail optical fiber and light source 1 and light path demodulating equipment 3 shaft angle degree is adjusted into 0 °-0 °, start to measure, obtain as the measurement result of Fig. 5,81 are expressed as the interference main peak of measurement, and it is measuring amplitude and light path position reference point; 82(82 '), 83(83 ') be the spuious interference peaks of measurement mechanism 3 light paths; 84(84 ') the relevant peak of high-order causing for light source light spectrum ripple; 85(85 ') be the polarization crosstalk Noise Background of measurement mechanism 3, represent the measuring limit of measurement mechanism;

(8), from step 708～709, adjustment I/O angle is respectively 0 °-45 °, 45 °-0 ° and again starts proving installation, can obtain Y waveguide the first output channel 2B as shown in Figure 6, Figure 7, the measurement result of the second output channel 2C;

(9) from step 710～711, according to optical fiber and waveguide chip length, calculate the light path amount of each several part, and sequence, 8A～8E is symmetrical respectively to obtain 8A～8E(8A '～8E '), 9A～9E is symmetrical respectively for 9A～9E(9A '～9E ') each 10 characteristic peaks, and by formula (7), determined implication and the concrete amplitude of each polarization crosstalk peak value, as shown in Figure 11 and Figure 12;

(10) from step 712, the extinction ratio that the first output channel and the second output channel are measured respectively waveguide chip is respectively 55.2 ± 0.2dB and 52.3 ± 0.2dB, and its difference is 2.9dB;

(11), from step 713～714, according to I/O extended fiber length, be respectively l _f-i=15.00 meters, l _f-o-1=l _f-o-2=5.60 meters, I/O tail optical fiber is respectively l _w-i=1.53 meters, l _w-o-1=1.72 meters, l _w-o-1=1.78 meters, waveguide chip length is 20mm, and refers to Figure 13 and Figure 14 according to the linear birefrigence that (7), (8) formula can calculate optical fiber and waveguide;

(12) known according to test data, the maximal value I (0) of the white light interference signal peak obtaining from first, second output channel _out1, I (0) _out2be respectively 2.8dBV, 3.9dBV, known two passage insertion loss differ 1.1dB.

Embodiment 3---the temperature variant measurement of Y waveguide device two output channel

The measurement mechanism of Y waveguide device still as shown in Figure 3, be with the difference part of embodiment 2, the Y waveguide to be measured 2 of an other connection and wide spectrum light source 1 and light path demodulating equipment 3 is placed in temperature-controlled cabinet, from-50 ℃, change to 80 ℃ and change temperature, according to measurement procedure and data analysing method as shown in Figure 4, from the first measurement passage and second, measure the various optics variation with temperature amounts that passage obtains Y waveguide device simultaneously.

Test findings shows: the Coupling point cross-talk of I/O tail optical fiber and waveguide chip is very responsive to temperature, as shown in Fig. 8～10, be respectively the power coupling cross-talk variation with temperature of Y waveguide input tail optical fiber, the first output channel tail optical fiber, the second output channel tail optical fiber and waveguide chip.As can be seen from the figure, three changes and is inconsistent, and waveguide input tail optical fiber cross-talk and the first output channel tail optical fiber cross-talk change (more than 20dB) greatly, and the second output channel tail optical fiber cross-talk changes less (in 10dB).The size of cross-talk variable quantity, the temperature of minimum cross-talk point etc. are relevant with material and the technique of optical fiber, waveguide junction.Therefore,, by first, second output channel cross-talk being varied with temperature to the analysis of curve, the choice and optimization of Y waveguide material and technique is had to very large directive significance.

Claims (5)

1. a binary channels optical performance test device for integrated waveguide modulator, comprises high polarization degree of stability wide spectrum light source (1), integrated waveguide modulator to be measured (2), light path demodulating equipment (3), polarization crosstalk detection and pen recorder (4), it is characterized in that:

The first output channel of integrated waveguide modulator to be measured (2) and the second output channel are connected to the first demodulated interferential instrument and the second demodulated interferential instrument of light path demodulating equipment (3); Polarization crosstalk detects and is connected the first demodulated interferential instrument and the second demodulated interferential instrument with pen recorder (4) simultaneously, and opto-electronic conversion and signal processing unit (41) are processed and record the white light interference signal of the second differential detector output in the first differential detector in the first demodulated interferential instrument and the second (FBG) demodulator simultaneously; Control polarization crosstalk identification and disposal route that computing machine (42) utilizes built-in integrated waveguide modulator to be measured (2), absolute value to the waveguide chip extinction ratio between the first output channel of integrated waveguide modulator to be measured (2) and the second output channel, linear birefrigence, insertion loss, tail optical fiber cross-talk is measured, Storage & Display, and the performance difference when external environment parameters or application parameter change is compared and shown.

2. the binary channels optical performance test device of a kind of integrated waveguide modulator according to claim 1, it is characterized in that: the first described demodulated interferential instrument and the second demodulated interferential instrument: the first demodulated interferential instrument (31) is connected with the first end of the one 2 * 2 fiber coupler (303) by the first optical fiber analyzer (301), the second end of the one 2 * 2 fiber coupler is connected with the first end of the 22 * 2 fiber coupler (307), the 3rd end of the one 2 * 2 fiber coupler is connected by the first optical fiber circulator (305) with the 4th end of the 22 * 2 fiber coupler (307), the 4th end of the one 2 * 2 fiber coupler is connected with a DFB light source (311), the other end of the first optical fiber circulator (305) connects the first fiber collimating lenses (306), the second end of the 22 * 2 fiber coupler (307) is connected the first differential detector with the 3rd end,

The second demodulated interferential instrument (32) is identical with the composition of the first demodulated interferential instrument, consists of respectively the second optical fiber analyzer (321), the 32 * 2 fiber coupler (323), the 42 * 2 fiber coupler (327), the second optical fiber circulator (325), the second fiber collimating lenses (326), the second differential detector, the 2nd DFB light source (331).

3. the binary channels optical performance test device of a kind of integrated waveguide modulator according to claim 1 and 2, it is characterized in that: described high polarization degree of stability wide spectrum light source (1), the first output terminal (13) by fiber coupler (12) is connected in the first photodetector (14); By the second output terminal (15), after fibre optic isolater (16), be connected in the optical fiber polarizer (17).

4. the binary channels optical performance test device of a kind of integrated waveguide modulator according to claim 3, is characterized in that: described integrated waveguide modulator to be measured (2) with the annexation of high polarization degree of stability wide spectrum light source (1) and light path demodulating equipment (3) is:

It is 0～45 ° to shaft angle degree that the output polarization maintaining optical fibre (18) of the optical fiber polarizer (17) is protected inclined to one side tail optical fiber (21) with the input of integrated waveguide modulator to be measured (2) input channel (2A);

What inclined to one side tail optical fiber and the first optical fiber analyzer of the first demodulated interferential instrument and the second demodulated interferential instrument were protected in first output channel (2B) of integrated waveguide modulator to be measured, the output of the second output channel (2C), inclined to one side tail optical fiber is protected in the input of the second optical fiber analyzer is respectively 0～45 ° to shaft angle degree.

5. the polarization crosstalk of the binary channels optical performance test device of integrated waveguide modulator is identified and a disposal route, it is characterized in that:

1) detect the length l that inclined to one side tail optical fiber (21) is protected in input _w-,, judge whether to meet:

S _W-i=l _W-i×Δn _f>S _ripple

In formula: Δ n _ffor protecting inclined to one side tail optical fiber linear birefrigence, S _ripplelight path maximal value for light source (11) Secondary coherence peak;

2) if do not met, weld an elongated segment polarization maintaining optical fibre l _f-i, to shaft angle degree, be 0 °-0 °, measure and record extended fiber l _f-ilength and theoretical light path S _f-i, judgement:

S _f-i=l _f-i×Δn _f>S _ripple

3) measure the length l of waveguide chip (2D) _w;

4) measure the length l of the first output channel tail optical fiber, the second output channel tail optical fiber _w-o-1, l _w-o-2, judgement:

S _w-o-1=l _w-o-1* Δ n _fand S _w-o-2=l _w-o-1* Δ n _f>S _w=l _w* Δ n _w

In formula: Δ n _wthe linear birefrigence of waveguide chip;

5) as the length l of output channel tail optical fiber _w-o-1, l _w-o-2do not meet the condition of step 4), in the first output channel, the second output channel, weld respectively the extended fiber l that two segment length are identical _f-o-1, l _f-o-2, it is 0 °-0 ° to shaft angle degree, its length requirement meets:

S _f-o-1=l _f-o-1* Δ n _fand S _f-o-2=l _f-o-1* Δ n _f>S _w=l _w* Δ n _w, measure and record extended fiber l _f-o-1, l _f-o-2;

6) integrated waveguide modulator to be measured (2) is connected with light path demodulating equipment (3) with wide spectrum light source (1), its input and and output shaft angle degree is respectively to θ ₁=45 °, θ ₂=45 °;

7) start white light interferometer, obtain two width distributed polarization crosstalk measurement result curve of the first output channel, the second output channel simultaneously;

8) utilize the geometrical length of the device each several part of having measured, comprising: inclined to one side tail optical fiber (21) length l is protected in input _w-i, input extends polarization maintaining optical fibre length l _f-i, waveguide chip (2D) length l _w, the first output channel, the second output channel tail optical fiber length l _w-o-1, l _w-o-2, output extended fiber length l _f-o-1, l _f-o-2; Calculate its optical path delay amount, and according to size, to be arranged in order be two row:

The corresponding first wave guide output channel of the first row: S _f-i, (S _f-i+ S _w-i), S _f-o-1, (S _f-o-1+ S _w-o-1), (S _f-o-1+ S _w-o-1+ S _f-i+ S _w-i+ S _w-1)

Corresponding the second waveguide output channel: the S of the second row _f-i, (S _f-i+ S _w-i), S _f-o-2, (S _f-o-2+ S _w-o-2), (S _f-o-2+ S _w-o-2+ S _f-i+ S _w-i+ S _w-2)

9) contrast with theoretical formula, determine the polarization crosstalk characteristic peak that the first output channel (2B) is measured, be specially:

(1) the polarization crosstalk ρ of waveguide input extended fiber and waveguide input tail optical fiber (21) _f-i;

(2) the polarization crosstalk ρ of waveguide input tail optical fiber (21) and waveguide chip (2D) _w-i;

(3) the polarization crosstalk ρ of output extended fiber and the first output channel waveguide output tail optical fiber _f-o-1;

The polarization crosstalk of (4) first output channel waveguide output tail optical fibers and waveguide chip (2D) _{ρ W-o-1};

(5) polarization crosstalk of the Y waveguide chip that first passage is measured

Determine the polarization crosstalk characteristic peak that the second output channel (2C) is measured, be specially:

(1) the polarization crosstalk ρ of waveguide input extended fiber and waveguide input tail optical fiber (21) _f-i;

(2) the polarization crosstalk ρ of waveguide input tail optical fiber (21) and waveguide chip (2D) _w-i;

(3) the polarization crosstalk ρ of output extended fiber and the second output channel waveguide output tail optical fiber _f-o-2;

The polarization crosstalk of (4) second output channel waveguide output tail optical fibers and waveguide chip (2D) _{ρ W-o-2};

(5) polarization crosstalk of the Y waveguide chip that second channel is measured

10) contrast polarization crosstalk

with polarization crosstalk

polarization crosstalk ρ _w-o-2with polarization crosstalk ρ _w-o-1;

11) according to the birefringence n of the polarization maintaining fiber pigtail calculating and waveguide chip actual measurement _f, Δ n _w; I (0) _out1/ I (0) _out2represent the insertion loss ratio that first, second output channel of waveguide device is measured;

12) when external environment parameters or application parameter variation, re-execute step 7), optical parametric to Y waveguide is measured, and the parameter that can measure also comprises the changes in optical properties of two output channels, comprises the coupling cross-talk variation with temperature of I/O optical fiber and waveguide chip; The chip extinction ratio of waveguide two output channels is with the variation of impressed voltage.

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