IEC 61300-3-6:2008

FOREWORD
1 Scope
2 Normative references
3 General description
  3.1 Method 1
  3.2 Method 2
  3.3 Method 3
  3.4 Method 4
  3.5 Selection of reference measurement method
4 Apparatus and symbols
  4.1 Device under test (DUT)
  4.2 Method 1: measurements with OCWR
      4.2.1 Branching device (BD)
      4.2.2 Detector (D[1], D[2] and D[3])
      4.2.3 Source (S[1] and S[2])
      4.2.4 Temporary joint (TJ)
      4.2.5 Termination (T)
  4.3 Method 2: measurements with OTDR
      4.3.1 Optical time domain reflectometer (OTDR)
      4.3.2 Fibre sections (L[1], L[2], and L[3])
      4.3.3 Temporary joints (TJ)
  4.4 Method 3: measurements with OLCR
      4.4.1 Light source (S)
      4.4.2 Branching device (BD)
      4.4.3 Optical delay line (ODL)
      4.4.4 Optical detector (D)
      4.4.5 Temporary joint (TJ)
      4.4.6 Data processing unit
  4.5 Method 4: measurements with an OFDR
      4.5.1 RF network analyser
      4.5.2 Optical heads - Source (S) and receiver (D)
      4.5.3 Optical variable attenuator (A) (optional)
      4.5.4 Optical amplifier (OA) (optional)
      4.5.5 Isolator (I) (optional)
      4.5.6 Branching device (BD)
      4.5.7 Temporary joint (TJ)
      4.5.8 Computer
5 Procedure
  5.1 Launch conditions
  5.2 Pre-conditioning
  5.3 DUT output port
  5.4 Method 1: measurement with OCWR
      5.4.1 Definition of the OCWR measurement
      5.4.2 Set-up characterization
      5.4.3 Measurement procedure
      5.4.4 Accuracy considerations
  5.5 Method 2: measurement with OTDR
      5.5.1 Definition of the OTDR measurement
      5.5.2 Evaluation of backscattering coefficient
      5.5.3 Measurement procedure
      5.5.4 Accuracy considerations
  5.6 Method 3: measurement with OLCR
      5.6.1 Calibration procedure
      5.6.2 Measurement procedure
      5.6.3 Accuracy considerations
  5.7 Method 4: measurements with OFDR
      5.7.1 Calibration procedure
      5.7.2 Measurement procedure
      5.7.3 Accuracy considerations
6 Details to be specified
  6.1 Return loss measurement with OCWR
      6.1.1 Reference components
      6.1.2 Branching device
      6.1.3 Detector
      6.1.4 Source
      6.1.5 Temporary joint
      6.1.6 Termination
  6.2 Return loss measurement with OTDR
      6.2.1 Reference components
      6.2.2 OTDR
      6.2.3 L[1], L[2], and L[3]
      6.2.4 Fibre
  6.3 Return loss measurement with OLCR
      6.3.1 Reference components
      6.3.2 Source
      6.3.3 Branching device (BD)
  6.4 Return loss measurement with OFDR
      6.4.1 Reference components
      6.4.2 Vector network analyser
      6.4.3 Branching device
      6.4.4 Source
      6.4.5 Detector
      6.4.6 Optical amplifier (optional)
      6.4.7 Isolator (optional)
      6.4.8 Calibration
  6.5 Measurement procedure
Annex A (informative) Comparison of return loss detectable by
                      four different methods

IEC 61300-3-6:2008 presents procedures for the measurement of the return loss (RL) of a fibre optic device under test (DUT). RL, as used in this standard, is the ratio of the power (Pi) incident on, or entering, the DUT to the total power reflected (Pr) by the DUT, expressed in decibels. This third edition cancels and replaces the second edition published in 2003. It constitutes a technical revision. The changes with respect to the previous edition are to reconsider the constitution of the document and launch conditions for multimode fibres.