IEC PAS 61300-3-38:2007

FOREWORD
1 Scope
2 Normative references
3 Terms, definitions and abbreviations
4 General description
5 Apparatus
  5.1 Modulation phase method
      5.1.1 Variable wavelength source
      5.1.2 Tracking filter
      5.1.3 Reference branching device (RBD1, 2)
      5.1.4 Wavelength monitor
      5.1.5 Device under test (DUT)
      5.1.6 Detector D1, D2 (optional)
      5.1.7 RF generator
      5.1.8 Amplitude modulator
      5.1.9 Phase comparator
      5.1.10 Temporary joints (TJ1-TJ2)
      5.1.11 Polarization controller
      5.1.12 Reference jumper
  5.2 Swept wavelength interferometry method
      5.2.1 Tunable laser source (TLS)
      5.2.2 Wavelength monitor
      5.2.3 Reference branching devices (RBD1, 2, 3)
      5.2.4 Detectors
      5.2.5 Polarization controller
      5.2.6 Polarization analyser
6 Measurement procedure
  6.1 Modulation phase shift method
      6.1.1 Measurement principle
      6.1.2 RF modulation frequency
      6.1.3 Test sequence
      6.1.4 Calculation of group delay
      6.1.5 Measurement window
  6.2 Swept wavelength interferometry method
      6.2.1 Measurement principle
      6.2.2 Test sequence
      6.2.3 Calculations of group delay
7 Analysis
  7.1 Noise reduction of group delay measurement
      7.1.1 Averaging
      7.1.2 Spectral filtering
  7.2 Linear phase variation
  7.3 Chromatic dispersion
      7.3.1 Finite difference calculation
      7.3.2 Curve fit
8 Test results
Annex A (informative) Calculation of differential group delay
  A.1 Calculation of DGD from measurements made with the MPS
      method at four states of input polarization
  A.2 Calculation of DGD from measurements made with the MPS
      method while scanning the states of input polarization
      ("all states method")
  A.3 Calculation of DGD from measurements made with the SWI
      method

The purpose of this PAS is to define the measurement methods necessary to characterize the group delay properties of passive components. From these measurements further parameters like group delay ripple, linear phase deviation, chromatic dispersion, and dispersion slope can be derived. In addition, when these measurements are made with resolved polarization, the differential group delay (DGD) can also be determined as an alternative to separate measurement with the dedicated methods of IEC 61300-3-32.