Rec. ITU-T G.650.1 (10/2020) Definitions and test methods for linear, deterministic attributes of single-mode fibre and cable
Summary
History
FOREWORD
Table of Contents
1 Scope
2 References
3 Definitions
3.1 General definitions
3.2 Mechanical characteristics
3.3 Glass geometry characteristics
3.4 Optical characteristics
3.4.1 mode field definitions
3.4.2 chromatic dispersion definitions
3.5 Others
4 Abbreviations and acronyms
5 Conventions
6 Test methods
6.1 Test methods for the mode field diameter
6.1.1 Reference test method: The far-field scan
6.1.1.1 General
6.1.1.2 Test apparatus
6.1.1.2.1 Light source
6.1.1.2.2 Modulation
6.1.1.2.3 Launching conditions
6.1.1.2.4 Cladding mode stripper
6.1.1.2.5 Specimen
6.1.1.2.6 Scan apparatus
6.1.1.2.7 Detector
6.1.1.2.8 Amplifier
6.1.1.2.9 Data acquisition
6.1.1.3 Measurement procedure
6.1.1.4 Presentation of the results
6.1.2 First alternative test method: The variable aperture technique
6.1.2.1 General
6.1.2.2 Test apparatus
6.1.2.2.1 Light source (as in clause 6.1.1.2.1)
6.1.2.2.2 Modulation (as in clause 6.1.1.2.2)
6.1.2.2.3 Launching conditions (as in clause 6.1.1.2.3)
6.1.2.2.4 Cladding mode stripper (as in clause 6.1.1.2.4)
6.1.2.2.5 Specimen (as in clause 6.1.1.2.5)
6.1.2.2.6 Aperture apparatus
6.1.2.2.7 Detector (as in clause 6.1.1.2.7)
6.1.2.2.8 Amplifier (as in clause 6.1.1.2.8)
6.1.2.2.9 Data acquisition (as in clause 6.1.1.2.9)
6.1.2.3 Measurement procedure
6.1.2.4 Presentation of the results
6.1.3 Second alternative test method: The near-field scan
6.1.3.1 General
6.1.3.2 Test apparatus
6.1.3.2.1 Light source (as in clause 6.1.1.2.1)
6.1.3.2.2 Modulation (as in clause 6.1.1.2.2)
6.1.3.2.3 Launching conditions (as in clause 6.1.1.2.3)
6.1.3.2.4 Cladding mode stripper (as in clause 6.1.1.2.4)
6.1.3.2.5 Specimen (as in clause 6.1.1.2.5)
6.1.3.2.6 Scan apparatus
6.1.3.2.7 Detector (as in clause 6.1.1.2.7)
6.1.3.2.8 Amplifier (as in clause 6.1.1.2.8)
6.1.3.2.9 Data acquisition (as in clause 6.1.1.2.9)
6.1.3.3 Measurement procedure
6.1.3.4 Presentation of the results
6.1.4 Third alternative test method: Bidirectional backscatter difference
6.1.4.1 General
6.1.4.2 Test apparatus
6.1.4.3 Measurement procedure
6.1.4.3.1 Measurement of a fibre at a given wavelength
6.1.4.3.2 Qualification for a fibre type, design and wavelength
6.1.4.4 Presentation of results
6.2 Test methods for the cladding diameter, core concentricity error and cladding non-circularity
6.2.1 Reference test method: The near-field image technique
6.2.1.1 General
6.2.1.2 Test apparatus
6.2.1.2.1 Light sources
6.2.1.2.2 Launching conditions
6.2.1.2.3 Cladding mode stripper
6.2.1.2.4 Specimen
6.2.1.2.5 Magnifying optics
6.2.1.2.6 Detector
6.2.1.2.7 Video image monitor
6.2.1.2.8 Data system
6.2.1.3 Measurement procedure
6.2.1.3.1 Calibration
6.2.1.3.2 Measurement
6.2.1.3.3 Calculations
6.2.1.4 Presentation of the results
6.2.2 First alternative test method: The refracted near-field technique
6.2.2.1 General
6.2.2.2 Test apparatus
6.2.2.2.1 Source
6.2.2.2.2 Launching conditions
6.2.2.2.3 Cell
6.2.2.2.4 Detection
6.2.2.2.5 Data acquisition
6.2.2.3 Procedure
6.2.2.3.1 Preparation of fibre under test
6.2.2.3.2 Equipment calibration
6.2.2.3.3 Raster scan
6.2.2.3.4 Geometrical characteristics
6.2.2.4 Presentation of the results
6.2.3 Second alternative test method: The side-view technique
6.2.3.1 General
6.2.3.2 Test apparatus
6.2.3.2.1 Light source
6.2.3.2.2 Specimen
6.2.3.2.3 Magnifying optics
6.2.3.2.4 Detector
6.2.3.2.5 Data processing
6.2.3.3 Measurement procedure
6.2.3.3.1 Equipment calibration
6.2.3.3.2 Measurement
6.2.3.4 Presentation of the results
6.2.4 Third alternative test method: The transmitted near-field technique
6.2.4.1 General
6.2.4.2 Test apparatus
6.2.4.2.1 Light source
6.2.4.2.2 Launching conditions
6.2.4.2.3 Mode filter
6.2.4.2.4 Cladding mode stripper
6.2.4.2.5 Specimen
6.2.4.2.6 Magnifying optics
6.2.4.2.7 Detector
6.2.4.2.8 Amplifier
6.2.4.2.9 Data acquisition
6.2.4.3 Measurement procedure
6.2.4.3.1 Equipment calibration
6.2.4.3.2 Measurement
6.2.4.4 Presentation of the results
6.3 Test methods for the cut-off wavelength
6.3.1 Reference test method for the fibre cut-off wavelength (λc) of the primary coated fibre: The transmitted power technique
6.3.1.1 General
6.3.1.2 Test apparatus
6.3.1.2.1 Light source
6.3.1.2.2 Modulation
6.3.1.2.3 Launching conditions
6.3.1.2.4 Cladding mode stripper
6.3.1.2.5 Optical detector
6.3.1.3 Measurement procedure
6.3.1.3.1 Standard test sample
6.3.1.3.2 Transmission through the reference sample
6.3.1.3.3 Calculations
6.3.1.3.4 Determination of cut-off wavelength
6.3.1.4 Presentation of the results
6.3.2 Reference test method for the cable cut-off wavelength (λcc): The transmitted power technique
6.3.2.1 General
6.3.2.2 Test apparatus
6.3.2.2.1 Light source (as in clause 6.3.1.2.1)
6.3.2.2.2 Modulation (as in clause 6.3.1.2.2)
6.3.2.2.3 Launching conditions (as in clause 6.3.1.2.3)
6.3.2.2.4 Cladding mode stripper (as in clause 6.3.1.2.4)
6.3.2.2.5 Optical detector (as in clause 6.3.1.2.5)
6.3.2.3 Measurement procedure
6.3.2.3.1 Standard test sample
6.3.2.3.2 Transmission through the reference sample (as in clause 6.3.1.3.2)
6.3.2.3.3 Calculations
6.3.2.3.4 Determination of cabled fibre cut-off wavelength
6.3.2.4 Presentation of the results
6.4 Test methods for attenuation
6.4.1 Reference test method: The cut-back technique
6.4.1.1 General
6.4.1.2 Test apparatus
6.4.1.2.1 Optical source
6.4.1.2.2 Modulation
6.4.1.2.3 Launching conditions
6.4.1.2.4 Mode filter
6.4.1.2.5 Cladding mode stripper
6.4.1.2.6 Optical detector
6.4.1.3 Measurement procedure
6.4.1.3.1 Preparation of fibre under test
6.4.1.3.2 Procedure
6.4.1.4 Presentation of the results
6.4.2 First alternative test method: The backscattering technique
6.4.2.1 General
6.4.2.2 Test apparatus
6.4.2.2.1 General considerations
6.4.2.2.2 Optical source
6.4.2.2.3 Optical coupling system
6.4.2.2.4 Branching device
6.4.2.2.5 Optical detector
6.4.2.2.6 Amplifier
6.4.2.2.7 Signal processor
6.4.2.2.8 Cladding mode stripper
6.4.2.2.9 Fibre sample configuration
6.4.2.3 Measurement procedure
6.4.2.4 Presentation of the results
6.4.3 Second alternative test method: The insertion loss technique
6.4.3.1 General
6.4.3.2 Test apparatus
6.4.3.2.1 Optical source
6.4.3.2.2 Modulation
6.4.3.2.3 Launching conditions
6.4.3.2.4 Reference system (option b) only)
6.4.3.2.5 Mode filter
6.4.3.2.6 Cladding mode stripper
6.4.3.2.7 Optical detection
6.4.3.3 Measurements procedure
6.4.3.3.1 Preparation of fibre under test
6.4.3.3.2 Procedure
6.4.3.4 Presentation of the results
6.4.4 Third alternative test method: Spectral attenuation modelling
6.4.4.1 General
6.4.4.2 Test apparatus
6.4.4.3 Calculation procedure
6.4.4.4 Presentation of the results
6.5 Test methods for chromatic dispersion
6.5.1 Reference test method: The phase-shift technique
6.5.1.1 General
6.5.1.2 Test apparatus
6.5.1.2.1 Optical source
6.5.1.2.2 Wavelength selection
6.5.1.2.3 Detector
6.5.1.2.4 Reference channel
6.5.1.2.5 Delay detector
6.5.1.2.6 Signal processor
6.5.1.3 Measurement procedure
6.5.1.4 Presentation of the results
6.5.2 Alternative test method: The pulse delay technique
6.5.2.1 General
6.5.2.2 Test apparatus
6.5.2.2.1 Optical source
6.5.2.2.2 Wavelength selection
6.5.2.2.3 Detector
6.5.2.2.4 Reference channel
6.5.2.2.5 Delay detector
6.5.2.2.6 Signal processor
6.5.2.3 Measurement procedure
6.5.2.4 Presentation of the results
6.6 Test methods for macrobend loss
6.6.1 Reference test method: Fibre winding
6.6.1.1 General
6.6.1.2 Measurement considerations
6.6.1.2.1 Sample length
6.6.1.2.2 Number of coils
6.6.1.2.3 Bend radius
6.6.1.2.4 Measurement wavelength
6.6.1.3 Test apparatus
6.6.1.3.1 Bending tool
6.6.1.3.2 Loss measurement instrument
6.6.1.4 Measurement procedure
6.6.1.5 Calculation
6.6.1.6 Presentation of the results
6.7 Test methods for proof testing
6.7.1 Reference test method: Longitudinal tension
6.7.1.1 General
6.7.1.1.1 Proof test parameters
6.7.1.2 Test apparatus
6.7.1.2.1 Operating procedure requirements
6.7.1.2.2 Proof test machines
6.7.1.3 Measurement procedure
6.7.1.3.1 Sample
6.7.1.3.2 Calculation
6.7.1.4 Presentation of the results
Annex A Chromatic dispersion fitting
A.1 General
A.2 Definition of equations and fitting coefficients
A.3 Fitting procedure
Appendix I Methods of cut-off wavelength interpolation
I.1 Limited negative error method
I.2 Least squares method
I.3 Example
Appendix II Test method for measuring longitudinal uniformity of chromatic dispersion based on the backscattering technique
II.1 General
II.2 Test apparatus
II.2.1 General considerations (as in clause 6.4.2.2.1)
II.2.2 Optical source (as in clause 6.4.2.2.2)
II.2.3 Optical coupling system (as in clause 6.4.2.2.3)
II.2.4 Branching device (as in clause 6.4.2.2.4)
II.2.5 Optical detector (as in clause 6.4.2.2.5)
II.2.6 Amplifier (as in clause 6.4.2.2.6)
II.2.7 Signal processor (as in clause 6.4.2.2.7)
II.2.8 Cladding mode stripper (as in clause 6.4.2.2.8)
II.2.9 Reference fibre
II.3 Measurement procedure
II.4 Presentation of the results
Appendix III Example of a matrix model
III.1 Example characterizing matrices for ITU-T G.652.D and ITU-T G.654.E fibre
III.2 Illustrative relationship with predictor wavelengths
Appendix IV Test methods for measuring coherent MPI in short optical fibre cables (jumpers)
IV.1 First test method: The narrowband ECL/PM technique
IV.1.1 General
IV.1.2 Test apparatus
IV.1.2.1 Optical source
IV.1.2.2 Polarization scrambler
IV.1.2.3 Mode stripping loop
IV.1.2.4 Optical receiver
IV.1.3 Measurements procedure
IV.1.3.1 Preparation of the fibre under test
IV.1.3.2 Baseline measurement
IV.1.3.3 Insert short-cabled fibre
IV.1.3.4 Short-cabled fibre measurement
IV.1.3.5 Calculations
IV.1.3.6 Presentation of the results
IV.2 Second test method: The wideband LED/OSA technique
IV.2.1 General
IV.2.2 Test apparatus
IV.2.2.1 Optical source
IV.2.2.2 Polarization scrambler
IV.2.2.3 Mode stripping loop
IV.2.2.4 Optical receiver
IV.2.3 Measurements procedure
IV.2.3.1 Preparation of the fibre under test
IV.2.3.2 Baseline measurement
IV.2.3.3 Insert short-cabled fibre
IV.2.3.4 Short-cabled fibre measurement
IV.2.3.5 Calculations
IV.2.3.6 Presentation of the results
IV.3 Third test method: The fibre stretching technique
IV.3.1 General
IV.3.2 Test apparatus
IV.3.2.1 Optical source
IV.3.2.2 Measurement settings
IV.3.2.2.1 Polarization scrambler
IV.3.2.2.2 Translation stage
IV.3.2.2.3 Sampling frequency
IV.3.2.2.4 Number of measurements
IV.3.2.2.5 Using a manual polarization scrambler
IV.3.2.3 Mode stripping loop
IV.3.2.4 Optical receiver
IV.3.3 Measurements procedure
IV.3.3.1 Preparation of the fibre under test
IV.3.3.2 Baseline measurement
IV.3.3.3 Insert short fibre test sample
IV.3.3.4 Short-cabled fibre measurement
IV.3.3.5 Calculations
IV.3.3.6 Presentation of the results
Appendix V The interferometric technique for chromatic dispersion measurement
V.1 General
V.2 Test apparatus
V.2.1 Optical source
V.2.2 Wavelength selector
V.2.3 Optical detector
V.2.4 Test equipment
V.2.5 Specimen
V.2.6 Data processing
V.3 Measurement procedure
V.4 Presentation of the results
Bibliography
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