CN101479577B - 用参考光纤布拉格光栅监控和测量偏振保持光纤内器件的光学性质的方法及由此制作的光纤部件 - Google Patents
用参考光纤布拉格光栅监控和测量偏振保持光纤内器件的光学性质的方法及由此制作的光纤部件 Download PDFInfo
- Publication number
- CN101479577B CN101479577B CN2007800190292A CN200780019029A CN101479577B CN 101479577 B CN101479577 B CN 101479577B CN 2007800190292 A CN2007800190292 A CN 2007800190292A CN 200780019029 A CN200780019029 A CN 200780019029A CN 101479577 B CN101479577 B CN 101479577B
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- fiber
- bragg grating
- fbg
- reflectivity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 48
- 239000000835 fiber Substances 0.000 title claims abstract description 45
- 230000003287 optical effect Effects 0.000 title claims abstract description 39
- 230000010287 polarization Effects 0.000 title claims abstract description 32
- 238000012544 monitoring process Methods 0.000 title abstract description 8
- 238000002310 reflectometry Methods 0.000 claims abstract description 58
- 238000001228 spectrum Methods 0.000 claims abstract description 49
- 238000005259 measurement Methods 0.000 claims abstract description 31
- 239000013307 optical fiber Substances 0.000 claims description 137
- 238000000985 reflectance spectrum Methods 0.000 claims description 56
- 238000002266 amputation Methods 0.000 claims description 9
- 230000008859 change Effects 0.000 claims description 5
- 230000005540 biological transmission Effects 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims 1
- 230000008878 coupling Effects 0.000 description 10
- 238000010168 coupling process Methods 0.000 description 10
- 238000005859 coupling reaction Methods 0.000 description 10
- 238000012360 testing method Methods 0.000 description 7
- 230000001105 regulatory effect Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 229940085805 fiberall Drugs 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 238000001579 optical reflectometry Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000011514 reflex Effects 0.000 description 2
- 230000001143 conditioned effect Effects 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000000411 transmission spectrum Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02057—Optical fibres with cladding with or without a coating comprising gratings
- G02B6/02076—Refractive index modulation gratings, e.g. Bragg gratings
- G02B6/0208—Refractive index modulation gratings, e.g. Bragg gratings characterised by their structure, wavelength response
- G02B6/021—Refractive index modulation gratings, e.g. Bragg gratings characterised by their structure, wavelength response characterised by the core or cladding or coating, e.g. materials, radial refractive index profiles, cladding shape
- G02B6/02109—Refractive index modulation gratings, e.g. Bragg gratings characterised by their structure, wavelength response characterised by the core or cladding or coating, e.g. materials, radial refractive index profiles, cladding shape having polarization sensitive features, e.g. reduced photo-induced birefringence
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35303—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using a reference fibre, e.g. interferometric devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35309—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer
- G01D5/35316—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer using a Bragg gratings
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35338—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using other arrangements than interferometer arrangements
- G01D5/35341—Sensor working in transmission
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35338—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using other arrangements than interferometer arrangements
- G01D5/35354—Sensor working in reflection
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
- G01M11/30—Testing of optical devices, constituted by fibre optics or optical waveguides
- G01M11/31—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter and a light receiver being disposed at the same side of a fibre or waveguide end-face, e.g. reflectometers
- G01M11/3181—Reflectometers dealing with polarisation
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
- Spectrometry And Color Measurement (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
本发明提供一种利用写入到偏振保持(PM)光纤的窄带光纤布拉格光栅(FBG)，测量和监控该PM光纤的偏振态(SOP)及类似物的方法。该PM光纤包括第一窄带参考FBG，该第一窄带参考FBG被用作测量和监控PM光纤的SOP的参考。由于PM光纤的双折射性质，参考FBG通常反射两个窄带光谱，一个沿慢轴的窄带光谱和一个沿快轴的窄带光谱，每个窄带光谱具有一个中心波长。通过测量反射光谱沿每个轴的强度，并通过用偏振控制器调节光纤，可以将光纤调节到预定的SOP。在将PM光纤调节到预定SOP之后，可以根据该预定SOP精确测量第二光栅或另一光学器件的光学性质。本发明的方法还可以被有利地用来精确测量反射率。
Description
相关申请的交叉参考
本专利申请要求于2006年5月23日在加拿大知识产权局提交的共同受让加拿大专利申请No.2,548,022的优先权。
技术领域
本发明一般涉及用于测量光纤和光学器件的光学性质的方法。更具体地，本发明一般涉及偏振保持光纤内光纤布拉格光栅的测量。
背景技术
光纤布拉格光栅(以下称“FBG”)已被广泛地用在光通信***、光纤激光器以及传感产业里。泵浦激光器的波长稳定器和滤光器只是FBG在光通信中众所周知的几个应用例子。
FBG通常可以写入任何类型的光纤中，无论它是单模光纤、多模光纤还是偏振保持(PM)光纤，亦或其他光纤。简而言之，PM光纤在保持沿光纤整个长度传输的光束的偏振方面具有特性。然而，PM光纤的FBG与写入到标准单模光纤的FBG相比，在制作和测量方面的复杂性增大，特别是在后者方面。这个增大的复杂性源于PM光纤的双折射性质，即PM光纤的折射率在慢轴上的比在快轴上的稍大。因此，写入到PM光纤的FBG的光学性质会取决于光沿慢轴耦合、沿快轴耦合还是沿慢轴和快轴的组合耦合而变化。因而，测量到的性质会取决于测量条件(例如光的耦合情况)而变化。举例来说，沿慢轴被所测量PM光纤的FBG反射的中心波长将比沿快轴反射的中心波长大。
因此，当需要用PM光纤测量FBG的光学性质或另一光学器件的光学性质时，需要测量偏振态(以下称“SOP”)。换句话说，在对写入到PM光纤的FBG(和其他光学器件)做光学测量期间，必须确定和监控快轴和慢轴之间的光功率比。
在完美的情形下，为此目的的理想测试装置应具有全PM构造。实际上，这种完美的装置包括全部都是偏振保持的器件和/或部件，像PM光源，PM耦合器，PM循环器等等。然而，对于一种全PM的装置，问题不仅在于过度的成本，而且还在于可用性。实际上，在一些情形下上述元件中的一些根本不存在。
现有技术中有采用参考FBG测量光学器件或光学部件的光学性质的方法。事实上，术语“参考光纤布拉格光栅”是由Martin在他的标题为“Use of a Sampled BraggGrating as an In-Fiber Optical Resonator for the Realization of a ReferencingOptical Frequency Scale for WDM Communications”(OFC’1997 Technical Digest，pp.284-285)的文章中首次引入的。然而，Martin有关“参考光纤布拉格光栅”的出版物仅将应用确定为光纤内光学波长/频率的参考。
1998年，Miller等人(美国专利US5,838,437)提出一种与参考FBG相组合用作波长和频率参考的固定光纤法布里-珀罗(FP)滤波器。
2000年，Davis等人(美国专利US6,118,914和US6,403,949)公开了采用温度稳定的FBG作为波长参考。
2003年，Valente等人(美国专利US6,658,171)提出一种叫做“光纤布拉格光栅偏振器”的技术。在他们的发明中，FBG被用作一个使光波产生偏振的部件。
最后，2004年，Peupelmann等人(美国专利US6,816,260)提出一种称为光纤偏振计的器件，其利用倾斜的FBG将光波耦合出去，耦合结果取决于SOP。因而，耦合光的一部分可被用来确定四个斯托克斯参数。然而，在Peupelmann的发明中，FBG是被用作将一部分光波耦合出去的工具而并不是用作参考。并且，他们的发明没有基于PM光纤的FBG。
所有这些参考文献和技术存在的问题在于它们都没提供一种在PM光纤内根据预定的SOP来精确测量FBG的光学性质的简单且有效的方法。因此，需要这样一种新颖的方法。
发明内容
相应地，本发明的第一个目标是提供一种精确测量PM光纤的SOP的方法。
本发明的另一个目标是提供一种使用参考FBG测量和监控PM光纤的SOP的方法。
本发明的再一个目标是提供一种容许调节PM光纤的SOP的方法。
本发明的又一个目标是提供一种精确测量写入到PM光纤的FBG的光学性质的方法。
在对将要描述的或在所附权利要求书中指出的示例性实施例理解的基础上，本发明其他及另外的目标和优点将显而易见，并且在实践中实施本发明的基础上，这里没有提到的各种优点将呈现给本领域的普通技术人员。
依照本发明，为了确定和监控PM光纤的SOP，PM光纤设有一个参考FBG，为PM光纤提供SOP参考。
可以理解，偏振态(SOP)通常取决于多个参数。然而，为简化目的，如上面所用和下面所用地，SOP的概念仅指的是偏振保持光纤的慢轴与快轴间的光功率分布。
更精确地，参考FBG作为窄带FBG，容许测量慢轴与快轴间的功率比。如从图1可见，当用光束照射时，该光束并不完全沿慢轴或沿快轴耦合，PM光纤内的窄带参考FBG呈现两个峰。这两个峰的功率强度指示出偏振相对于慢轴和快轴的取向。因此，通过测量这两个峰的功率强度，可以测量出SOP。
通过调节PM光纤的取向，并通过连续监控参考FBG的SOP，本发明的方法容许将PM光纤调节成任何预定的SOP。
而且，如果另一个FBG形成在或写入到PM光纤上，那么该PM光纤的参考FBG将为要测量的FBG提供SOP的参考。如果需要，要确定的FBG的光谱可以通过在任何定义的SOP中将偏振取向调节为所需情形加以测量。
根据设备的需要和/或可用性，参考FBG可以在透射光谱或在反射光谱中实施光学SOP的监控功能。
通常，在宽带FBG下，例如带宽大于0.5nm的FBG，快轴和慢轴的反射峰将重叠，从而导致很难精确地确定当前正测量的FBG所处的SOP。然而，如果将窄带参考FBG引入到与要测量的FBG相同的光纤环内，那么该窄带参考FBG将精确地、独立地指出该光纤的SOP。当然，在该参考FBG与要测量的FBG之间应当有足够的波长差，以避免不希望有的重叠。另外，如果光纤环被这样配置，即使得光纤的SOP的可调性成为可能，那么对于测量中的FBG，任何预定的SOP都可以实现。
还已经发现，本发明用来根据具体的SOP确定FBG的光学性质的装置也可以用来精确测量在检查中的FBG的光反射率。因此，本发明还容许通过用参考FBG，对FBG或其他光学部件、器件和子***进行光反射率测量。
参考FBG可提供绝对的光功率强度参考，它的反射率用已知的反射或透射光谱测量法预先确定。一旦该参考反射率确定下来，其他FBG或器件/子***的反射率可以基于它们相对于参考FBG的反射率的峰强度值的功率强度差进行确定。
测量和/或调节偏振保持光纤的偏振态的方法，包括：
提供所述偏振保持光纤，所述偏振保持光纤确定一慢轴和一快轴，所述光纤具有一取向；
将窄带参考光纤布拉格光栅写入到所述光纤，所述参考光纤布拉格光栅具有第一反射光谱和第一透射光谱；
通过所述光纤发送光束；
探测所述参考光纤布拉格光栅的所述第一透射光谱或所述第一反射光谱；
测量所述第一透射光谱或第一反射光谱的第一峰的第一强度，所述第一峰与所述光纤的所述慢轴相关；
测量所述第一透射光谱或第一反射光谱的第二峰的第二强度，所述第二峰与所述光纤的所述快轴相关；
通过比较所述第一强度和所述第二强度，确定所述光纤的所述偏振态；
其中所述窄带参考光纤布拉格光栅还确定参考反射率；
调节所述光纤的所述取向，以基本减小所述第一反射光谱的所述第一峰的所述第一强度，或基本减小所述第一反射光谱的所述第二峰的所述第二强度；
测量所述参考反射率；
将第二光纤布拉格光栅写入到所述光纤，所述第二光纤布拉格光栅具有第二反射光谱和第二透射光谱，所述第二反射光谱不同于所述第一反射光谱，所述第二透射光谱不同于所述第一透射光谱，所述第二光纤布拉格光栅具有第二反射率；
测量所述第一和第二反射光谱内所述参考反射率和所述第二反射率之间的差；
通过比较所述参考反射率与所述参考反射率和所述第二反射率之间的差，确定所述第二反射率。
一种测量写入到光纤的光纤布拉格光栅的反射率的方法，包括步骤：
提供所述光纤；
将参考光纤布拉格光栅写入到所述光纤，所述参考光纤布拉格光栅确定一参考反射光谱和一参考透射光谱，所述参考光纤布拉格光栅具有参考反射率；
通过所述光纤发送光束；
测量在所述参考反射光谱内的所述参考光纤布拉格光栅的所述参考反射率的强度；
将第二光纤布拉格光栅写入到所述光纤，所述第二光纤布拉格光栅确定一第二反射光谱和一第二透射光谱，所述第二光纤布拉格光栅具有第二反射率；
测量所述参考光谱和第二反射光谱内的所述参考反射率与所述第二反射率之间的差；
通过比较所述参考反射率与所述参考反射率和所述第二反射率之间的差，确定所述第二反射率。
这种方法可适用于接近或超出透射光谱测量仪器的极限的超低反射率测量。这种方法还适用于非单模光纤内的FBG的反射率测量，在非单模光纤内，由于模式之间的光学干涉，在透射结构下进行反射率的精确测量很难。
另外，只要反射的光谱不重叠，本发明的参考FBG法可以应用于SOP测量和/或应用于对不止一个FBG的反射率测量。而且，本发明的参考FBG法可以根据应用情况采用单个参考FBG或多个参考FBG。同时，该方法可以用来测量除FBG外的光学器件和***的SOP和反射率。可以理解，如果应用的话，参考FBG可以形成在或写入到除光纤外的光波导。
而且，通过提供反射率参考FBG和SOP参考FBG，它们可以是一个或不同个，就可以将SOP相关的测量法和***与反射率的测量法和***组合到单个应用中。
本发明相信为新颖的这些特征具体阐述在所附权利要求书中。
附图说明
参看下面的详细描述并参看附图，本发明将变得更好理解。在附图中：
图1是写入到PM光纤的参考FBG的透射光谱的视图；
图2是通过采用参考FBG测量FBG的光学性质的装置的一个实施例的示意图；
图3是参考FBG和要测量的FBG的反射光谱的视图。
具体实施方式
首先参看图2，可以看到依照本发明的方法的一个优选实施例的装置的框图。该装置一般包括宽带光源(BBS)10，循环器20，在测量写入到PM光纤的FBG的光学性质的情形中的偏振控制器30，至少一个参考FBG 40，至少一个要测量的FBG50，以及光谱分析仪(以下称“OSA”)70。
应当理解，这种具体设置是一个优选的实施例。因此，可以用其他具备相同功能的设备替代该装置的一些部件。例如，宽带光源10可以用在宽光谱上扫描的可调激光器代替。
从宽带激光源10输出的光光学地耦合到循环器20的输入22，循环器20的输出连接到偏振控制器30的输入。控制器30的输出端口本身连接到PM光纤上，该PM光纤包括第一反射FBG 40、要测量的FBG 50以及光纤末梢60，该光纤末梢60优选地用光学折射率匹配的胶密封起来以避免费涅尔反射。循环器20的返回端口26连接在用于测量反射光谱的OSA 70上。可以理解，参考FBG 40和要测量的FBG 50可以设置在两根不同的光纤上，该两根光纤在测量之前接合在一起。
本发明的窄带参考FBG 40通常用UV光子写入。PM光纤的当前SOP通过测量在反射光谱或透射光谱中参考FBG 40的反射率来确定。图1中出示在透射光谱中这样测量的一个例子。如从图1可见，透射光谱显示出两个不同的峰。最左边峰的中心波长是参考FBG沿快轴被反射的波长，而最右边峰的中心波长是参考FBG沿慢轴被反射的波长。
通过测量每个峰的实际强度，可以确定PM光纤的实际SOP。因此，通过用偏振控制器30调节PM光纤，并连续监控参考FBG的SOP，可以将PM调节到预定的SOP。最终，如果需要，可以将光完全只耦合到慢轴或快轴。这种完全耦合通常可以借助于出现有单个较大峰来探测到。
然而，所属领域的技术人员将理解，为了区别开慢轴峰与快轴峰，需要采用窄带参考FBG。
一旦PM光纤的SOP被确定，并且如果需要，PM光纤的SOP被调节，则接下来的步骤是根据测试需求和/或设备的可用性，测量FBG或要在透射光谱或反射光谱中加以测量的FBG的光学性质。然而，由于SOP已经被预先确定，因此在这个步骤中测量的光学性质将反映出这个预定SOP。
能够理解，要测量的FBG可以是早已写入PM光纤，或者是在PM光纤的SOP用参考FBG做出测量和/或调节之后写入PM光纤。
前述的这种方法可以被有利地使用，以提供一种制作相对于某个SOP具有预定光学性质的FBG的有效方式。相应地，将参考FBG优选地写入到长PM光纤，例如具有100米长度的PM光纤的一个末端。随后，用偏振控制器30调节SOP。在得到特定的SOP后，将第一FBG优选地写入到该光纤的另一末端。在对该第一FBG的一个或多个光学性质测量和/或调节，并验证这个或这些光学性质是足够的之后，采用已知的方法截除该光纤载有第一FBG的部分。然后，将第二FBG写入到现在稍短的光纤的末端。再次地，在对该第二FBG的一个或多个光学性质测量和/或调节，并且验证这个或这些光学性质是足够的之后，截除该光纤载有第二FBG的部分。这个过程继续进行，直至所有可用光纤都被截除。可以理解，对于每个新的FBG，SOP可以重新调节或改变。
本发明这种方法的另一个优点是通过将反射波长或光谱的强度与参考FBG提供的参考强度相比较，可以将这种方法修改成精确测量FBG的反射率。实际上，在参考FBG写入光纤时，可以相对于PM光纤情形下的给定轴，将该FBG的折射率调节成预定的且易于测量的值。
图3示出用参考FBG在反射光谱内测量FBG反射率的一个例子。在图3中，有三条光谱。从左到右依次是FBG处于测量310下的反射光谱，参考FBG沿快轴320的反射光谱，以及参考FBG沿慢轴330的反射光谱。
根据前述的方法，通过用偏振控制器30调节PM光纤的SOP，并通过用参考FBG监控SOP，可以根据任何SOP，简单地测量处于测量中的FBG的反射率。可以理解，在普通的单模或多模光纤内，不需要任何SOP调节。
在PM光纤已被调节成特定SOP时，要测量的FBG的反射率可以比对(compareto)参考FBG的反射率。在图3的例子中，参考FBG 330的反射率用已知方法测量。这个参考FBG最优选地是窄带宽FBG，它的快轴和慢轴反射可以在反射光谱里很容易地区别开。在图3中，慢轴330的反射光谱是最右边的光谱，而快轴320的反射光谱是紧邻最右边慢轴光谱330的较小光谱。
如图3所示，通过用偏振控制器30调节光纤以实现沿慢轴的最大光耦合，快轴反射320已被基本抑制或减小。用这种方式，保证测试中的FBG的光谱测量沿慢轴进行。
然而，通过用偏振控制器30控制光耦合，同时观察参考FBG的两个峰的相对强度，可以在任何预定的SOP下对测试中的FBG进行测量。因此，如果做出适当配置，该参考FBG不仅能在反射光谱而且能在透射光谱里实施光学SOP的监控功能或指示功能。
在为基础(underlying)测试或测量获得合适的SOP之后，可以通过测量参考FBG的反射峰强度与测试中的FBG的峰强度之间的差，对测试中的FBG精确地执行反射率测量。很显然，只要反射光谱不重叠，如上所述的反射率测量和SOP参考这种方法可以同时应用于不止一个FBG和/或使用不止一个参考FBG。
而且，即使前述的反射率测量法和***是用PM光纤描述地，但是应当理解，这种方法可以在不脱离本发明的精神下实现在单模光纤和多模光纤上。然而，由于单模光纤和多模光纤一般地不显示双折射性质，因此当使用单模光纤或多模光纤时，不需要调节光纤的SOP。在这些情形下，参考FBG只提供反射率强度的参考。
另外，如上面对SOP测量法所述地，反射率测量法可以被有利地采用，以提高FBG的制造率。实际上，参考FBG可以优选写入到长光纤例如具有100米长度的光纤的一端。这样能精确地测量反射率，从而确定参考反射率。第一FBG优选写入光纤的另一末端。在对第一FBG的反射率测量和/或调节，并验证该反射率是足够的之后，用已知方法截除该光纤载有第一FBG的那部分。然后，第二FBG优选写入现在稍短的光纤的末端。再次地，在对该第二FBG的反射率测量和/或调节，并验证该反射率是足够的之后，截除该光纤载有第二FBG的那部分。这个过程继续进行，直至所有可用的光纤都被截除。
虽然这里详细描述了本发明的优选实施例并用附图示出，但是应当理解，本发明不限于这些确切的实施例，只要不脱离本发明的范围或精神，可以对本发明做出各种变化和改变。
Claims (14)
1.一种测量偏振保持光纤的偏振态的方法，所述方法包括：
提供所述偏振保持光纤，所述偏振保持光纤确定一慢轴和一快轴，所述光纤具有一取向；
将窄带参考光纤布拉格光栅写入到所述光纤，所述窄带参考光纤布拉格光栅具有第一反射光谱和第一透射光谱；
通过所述光纤发送光束；
探测所述窄带参考光纤布拉格光栅的所述第一透射光谱或所述第一反射光谱；
测量所述第一透射光谱或第一反射光谱的第一峰的第一强度，所述第一峰与所述光纤的所述慢轴相关；
测量所述第一透射光谱或第一反射光谱的第二峰的第二强度，所述第二峰与所述光纤的所述快轴相关；
通过比较所述第一强度和所述第二强度，确定所述光纤的所述偏振态；
将第二光纤布拉格光栅写入到所述光纤，所述第二光纤布拉格光栅具有第二反射光谱和第二透射光谱，所述第二反射光谱不同于所述第一反射光谱，所述第二透射光谱不同于所述第一透射光谱；
测量所述第二光纤布拉格光栅的至少一个光学性质。
2.如权利要求1的方法，其中所述探测所述参考光纤布拉格光栅的所述第一透射光谱或所述第一反射光谱的步骤用光谱分析仪实现。
3.如权利要求1的方法，其中所述通过所述光纤发送光束的步骤用宽带光源实现。
4.如权利要求1的方法，其中所述通过所述光纤发送光束的步骤用可调激光器实现。
5.如权利要求1的方法，所述方法还包括步骤：
调节所述光纤的所述取向，以改变所述偏振态。
6.如权利要求5的方法，其中所述调节所述光纤的所述取向的步骤用偏振空制器实现。
7.一种测量偏振保持光纤的偏振态的方法，所述方法包括：
提供所述偏振保持光纤，所述偏振保持光纤确定一慢轴和一快轴，所述光纤具有一取向；
将窄带参考光纤布拉格光栅写入到所述光纤，所述窄带参考光纤布拉格光栅具有第一反射光谱和第一透射光谱；
通过所述光纤发送光束；
探测所述窄带参考光纤布拉格光栅的所述第一透射光谱或所述第一反射光谱；
测量所述第一透射光谱或第一反射光谱的第一峰的第一强度，所述第一峰与所述光纤的所述慢轴相关；
测量所述第一透射光谱或第一反射光谱的第二峰的第二强度，所述第二峰与所述光纤的所述快轴相关；
通过比较所述第一强度和所述第二强度，确定所述光纤的所述偏振态；
其中所述窄带参考光纤布拉格光栅还确定参考反射率；
调节所述光纤的所述取向，以基本减小所述第一反射光谱的所述第一峰的所述第一强度，或基本减小所述第一反射光谱的所述第二峰的所述第二强度；
测量所述参考反射率；
将第二光纤布拉格光栅写入到所述光纤，所述第二光纤布拉格光栅具有第二反射光谱和第二透射光谱，所述第二反射光谱不同于所述第一反射光谱，所述第二透射光谱不同于所述第一透射光谱，所述第二光纤布拉格光栅具有第二反射率；
测量所述第一反射光谱内所述参考反射率和所述第二反射光谱内所述第二反射率之间的差；
通过比较所述参考反射率与所述参考反射率和所述第二反射率之间的差，确定所述第二反射率。
8.一种测量写入到光纤的光纤布拉格光栅的反射率的方法，所述方法包括步骤：
提供所述光纤；
将参考光纤布拉格光栅写入到所述光纤，所述参考光纤布拉格光栅确定一参考反射光谱和一参考透射光谱，所述参考光纤布拉格光栅具有参考反射率；
通过所述光纤发送光束；
测量在所述参考反射光谱内的所述参考光纤布拉格光栅的所述参考反射率的强度；
将第二光纤布拉格光栅写入到所述光纤，所述第二光纤布拉格光栅确定一第二反射光谱和一第二透射光谱，所述第二光纤布拉格光栅具有第二反射率；
测量所述参考反射光谱和第二反射光谱内的所述参考反射率与所述第二反射率之间的差；
通过比较所述参考反射率与所述参考反射率和所述第二反射率之间的差，确定所述第二反射率。
9.一种制作包含至少一个光纤布拉格光栅的偏振保持光纤的至少一部分的方法，所述方法包括：
a.提供所述偏振保持光纤，所述光纤具有第一和第二末端，所述偏振保持光纤确定一慢轴和一快轴，所述光纤具有一取向；
b.将窄带参考光纤布拉格光栅写入到所述光纤靠近所述第一末端的第一部分，所述窄带参考光纤布拉格光栅确定一参考反射光谱和一参考透射光谱；
c.通过所述光纤发送光束；
d.探测所述窄带参考光纤布拉格光栅的所述参考透射光谱或所述参考反射光谱；
e.测量所述参考透射光谱或所述参考反射光谱内的第一参考峰的第一参考强度，所述第一参考峰与所述光纤的所述慢轴相关；
f.测量所述参考透射光谱或所述参考反射光谱内的第二参考峰的第二参考强度，所述第二参考峰与所述光纤的所述快轴相关；
g.通过比较所述第一参考强度和所述第二参考强度，确定所述光纤的偏振态；
h.如果需要，通过改变所述光纤的所述取向，调节所述光纤的所述偏振态；
i.将第二光纤布拉格光栅写入到所述光纤邻近第二末端的第二部分；
j.测量所述第二光纤布拉格光栅的至少一个光学性质；
k.截除所述光纤的所述第二部分。
10.如权利要求9的方法，所述方法还包括步骤：
l.将第三光纤布拉格光栅写入到所述光纤邻近所述第二末端的第三部分；
m.测量所述第三光纤布拉格光栅的至少一个光学性质；
n.截除所述光纤的所述第三部分。
11.如权利要求10的方法，其中重复步骤l、m和n，直至基本上所有所述光纤被截除。
12.一种载有依照权利要求9制作的包含至少一个光纤布拉格光栅的偏振保持光纤部分。
13.一种载有依照权利要求10制作的包含至少一个光纤布拉格光栅的偏振保持光纤部分。
14.一种载有依照权利要求11制作的包含至少一个光纤布拉格光栅的偏振保持光纤部分。
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2,548,022 | 2006-05-23 | ||
| CA2548022A CA2548022C (en) | 2006-05-23 | 2006-05-23 | Method for monitoring and measuring optical properties of device in polarization maintaining fibers by using reference fiber bragg grating and fiber components manufactured thereby |
| PCT/CA2007/000904 WO2007134453A2 (en) | 2006-05-23 | 2007-05-23 | Method for monitoring and measuring optical properties of device in polarization maintaining fibers by using reference fiber bragg grating and fiber components manufactured thereby |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101479577A CN101479577A (zh) | 2009-07-08 |
| CN101479577B true CN101479577B (zh) | 2012-05-23 |
Family
ID=38719396
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007800190292A Active CN101479577B (zh) | 2006-05-23 | 2007-05-23 | 用参考光纤布拉格光栅监控和测量偏振保持光纤内器件的光学性质的方法及由此制作的光纤部件 |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US8154715B2 (zh) |
| EP (1) | EP2024718A4 (zh) |
| CN (1) | CN101479577B (zh) |
| AU (1) | AU2007252194A1 (zh) |
| CA (1) | CA2548022C (zh) |
| WO (1) | WO2007134453A2 (zh) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102393292B (zh) * | 2011-08-15 | 2013-06-26 | 西安盛佳光电有限公司 | 一种在保偏光纤中刻写光栅时的光栅参数测量方法及其装置 |
| CN102323042A (zh) * | 2011-09-08 | 2012-01-18 | 中国科学院半导体研究所 | 精确测量弱光纤光栅反射率的方法 |
| CN102829958A (zh) * | 2012-08-10 | 2012-12-19 | 中国电子科技集团公司第四十一研究所 | 精确测量光纤光栅反射率的方法 |
| CN103411757B (zh) * | 2013-09-04 | 2017-01-11 | 中国计量科学研究院 | 基于特定空间频率内窥镜光学传递函数测量***及其校准方法 |
| CN104792502B (zh) * | 2015-04-29 | 2017-12-08 | 重庆大学 | 一种测量弱光纤光栅反射率的方法 |
| CN107764514A (zh) * | 2016-08-22 | 2018-03-06 | 南京理工大学 | 一种高功率光纤激光器用低反光栅反射率精确测量装置 |
| CN112098039B (zh) * | 2020-09-08 | 2021-06-18 | 中国科学院力学研究所 | 一种高超声速流场脉动密度测量***及测量方法 |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6816260B2 (en) * | 2001-05-17 | 2004-11-09 | Thorlabs Gmbh | Fiber polarimeter, the use thereof, as well as polarimetric method |
| US6856401B1 (en) * | 1999-06-23 | 2005-02-15 | Optoplan As | Elimination of polarization fading in unbalanced optical measuring interferometers |
| CN1584536A (zh) * | 2003-07-05 | 2005-02-23 | 卡尔蔡司Smt股份公司 | 用于偏振特定研究的装置、光学成像***和校准方法 |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO302441B1 (no) * | 1995-03-20 | 1998-03-02 | Optoplan As | Fiberoptisk endepumpet fiber-laser |
| NO321724B1 (no) * | 1999-06-15 | 2006-06-26 | Optoplan As | Framgangsmate og anordning for malinger av de ortogonalt polariserte Bragg-bolgelengdene fra fiber-Bragg-gitter |
| US6856398B2 (en) * | 2001-10-24 | 2005-02-15 | Exfo Electro-Optical Engineering Inc. | Method of and apparatus for making wavelength-resolved polarimetric measurements |
| US7116887B2 (en) * | 2002-03-19 | 2006-10-03 | Nufern | Optical fiber |
| WO2006032116A1 (en) * | 2004-09-22 | 2006-03-30 | Faculte Polytechnique De Mons | Method for evaluating the influence of temperature and strain on the spectrum reflected by fibre bragg grating |
-
2006
- 2006-05-23 CA CA2548022A patent/CA2548022C/en active Active
-
2007
- 2007-05-23 AU AU2007252194A patent/AU2007252194A1/en not_active Abandoned
- 2007-05-23 CN CN2007800190292A patent/CN101479577B/zh active Active
- 2007-05-23 WO PCT/CA2007/000904 patent/WO2007134453A2/en active Application Filing
- 2007-05-23 EP EP07719826A patent/EP2024718A4/en not_active Withdrawn
- 2007-05-23 US US12/301,876 patent/US8154715B2/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6856401B1 (en) * | 1999-06-23 | 2005-02-15 | Optoplan As | Elimination of polarization fading in unbalanced optical measuring interferometers |
| US6816260B2 (en) * | 2001-05-17 | 2004-11-09 | Thorlabs Gmbh | Fiber polarimeter, the use thereof, as well as polarimetric method |
| CN1584536A (zh) * | 2003-07-05 | 2005-02-23 | 卡尔蔡司Smt股份公司 | 用于偏振特定研究的装置、光学成像***和校准方法 |
Non-Patent Citations (3)
| Title |
|---|
| Marc Wuilpart et al..Polarization properties of uniform fiber Bragg gratings written in highly birefringent fibers.Optics Communications.2005,247(4-6),239-245. |
| Marc Wuilpart et al..Polarization properties of uniform fiber Bragg gratings written in highly birefringent fibers.Optics Communications.2005,247(4-6),239-245. * |
| S.Lee et al..Adjustable compensation of polarization mode dispersion using a high-birefringence nonlinearly chirped fiber bragg grating.IEEE PHOTONICS TECHNOLOGY LETTERS.1999,11(10),全文. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101479577A (zh) | 2009-07-08 |
| CA2548022A1 (en) | 2007-11-23 |
| CA2548022C (en) | 2014-03-25 |
| WO2007134453A3 (en) | 2008-01-10 |
| WO2007134453A2 (en) | 2007-11-29 |
| US8154715B2 (en) | 2012-04-10 |
| US20100225914A1 (en) | 2010-09-09 |
| EP2024718A4 (en) | 2011-12-14 |
| EP2024718A2 (en) | 2009-02-18 |
| AU2007252194A1 (en) | 2007-11-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101479577B (zh) | 用参考光纤布拉格光栅监控和测量偏振保持光纤内器件的光学性质的方法及由此制作的光纤部件 | |
| US6925230B2 (en) | Long period chiral fiber grating apparatus | |
| JP6021285B2 (ja) | 光デバイスおよびファイバブラッググレーティングの使用方法 | |
| JP2017032979A (ja) | 高後方散乱導波路 | |
| US11391645B2 (en) | Birefringent multi-peak optical reference element and birefringent sensor system | |
| Shao et al. | High-resolution refractive index sensing with dual-wavelength fiber laser | |
| CN104613889B (zh) | 一种基于光纤环形激光器的弯曲传感测量*** | |
| US9395242B2 (en) | Broadband fiber sensor array | |
| US7424194B2 (en) | Single polarization fiber and method of evaluating fiber cutoff wavelengths using optical time domain reflectometry | |
| JP2007085754A (ja) | 光パルス試験器及び光ファイバ長手方向特性試験方法 | |
| CN108872150A (zh) | 一种双波长增益竞争折射率测量装置 | |
| KR100368122B1 (ko) | 반사대역폭이 외부 인가 스트레인에 따라 변하는 처핑된 광섬유 격자 센서 및 이를 이용한 스트레인 측정 장치 | |
| Xian et al. | Cladding mode coupling in a wide-band fiber Bragg grating and its application to a power-interrogated temperature sensor | |
| Rajan et al. | Effect of polarisation-dependent loss on the performance accuracy of a ratiometric wavelength measurement system | |
| AU2015203786A1 (en) | Method for monitoring and measuring optical properties of device in polarization maintaining fibers by using reference fiber Bragg grating and fiber components manufactured thereby | |
| Ding et al. | Sapphire fiber Bragg grating coupled with graded-index fiber lens | |
| AU2013270641A1 (en) | Method for monitoring and measuring optical properties of device in polarization maintaining fibers by using reference fiber bragg grating and fiber components manufactured thereby | |
| EP4258052A1 (en) | Supercontinuum system with spectral detection | |
| Travagnin et al. | Measurement of optical fiber macrobending losses in a single turn with continuously-varying radius | |
| Rajan et al. | Passive all-fiber wavelength measurement systems: Performance determination factors | |
| US7646951B2 (en) | Apparatus for manufacturing optical fiber Bragg grating, optical fiber, and mid-infrared optical fiber laser | |
| JP2002131186A (ja) | 光部品の偏波クロストークの測定方法 | |
| Zhao | Slanted multimode fiber gratings and applications | |
| Delgado-Pinar et al. | Characterization of thermal effects in fiber components using whispering-gallery modes resonances | |
| Chen et al. | Characterization of Hole-Assisted Fibers as Single Polarization Fibers and Polarization Maintaining Fibers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20160115 Address after: Montreal Patentee after: ITF LAB INC Address before: Quebec Patentee before: ITF Lab Inc. |