IEC 61315:2019

IEC 61315 ®
Edition 3.0 2019-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Calibration of fibre-optic power meters

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IEC 61315 ®
Edition 3.0 2019-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Calibration of fibre-optic power meters

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.140; 33.180.10 ISBN 978-2-8322-6732-5

– 2 – IEC 61315:2019 RLV © IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions. 7
4 Preparation for calibration . 16
4.1 Organization. 16
4.2 Traceability . 17
4.3 Advice for measurements and calibrations . 17
4.4 Recommendations to customers users . 18
5 Absolute power calibration . 18
5.1 Calibration methods . 18
5.2 Establishing the calibration conditions . 19
5.3 Calibration procedure . 20
5.4 Calibration uncertainty . 21
5.4.1 General . 21
5.4.2 Uncertainty due to the setup . 22
5.4.3 Uncertainty of the reference meter . 22
5.4.4 Correction factors and uncertainty caused by the change of conditions . 23
5.4.5 Uncertainty due to the test meter spectral bandwidths . 27
5.5 Reporting the results . 28
6 Measurement uncertainty of a calibrated power meter . 28
6.1 Overview . 28
6.2 Uncertainty at reference conditions . 28
6.3 Uncertainty at operating conditions . 29
6.3.1 General . 29
6.3.2 Determination of dependences on conditions . 30
6.3.3 Ageing . 30
6.3.4 Dependence on temperature . 31
6.3.5 Dependence on the power level (nonlinearity). 31
6.3.6 Dependence on the type of fibre or on the beam geometry . 31
6.3.7 Dependence on the connector-adapter combination . 33
6.3.8 Dependence on wavelength . 33
6.3.9 Dependence on spectral bandwidth . 34
6.3.10 Dependence on polarization . 35
6.3.11 Other dependences . 35
7 Nonlinearity calibration . 35
7.1 General . 35
7.2 Nonlinearity calibration based on superposition . 36
7.2.1 General . 36
7.2.2 Procedure . 37
7.2.3 Uncertainties. 38
7.3 Nonlinearity calibration based on comparison with a calibrated power meter . 39
7.3.1 General . 39
7.3.2 Procedure . 39

7.3.3 Uncertainties. 39
7.4 Nonlinearity calibration based on comparison with an attenuator . 40
7.5 Calibration of power meter for high power measurement . 40
Annex A (normative) Mathematical basis for measurement uncertainty calculations . 41
A.1 General . 41
A.2 Type A evaluation of uncertainty . 41
A.3 Type B evaluation of uncertainty . 42
A.4 Determining the combined standard uncertainty . 42
A.5 Reporting . 43
Annex B (informative) Linear to dB scale conversion of uncertainties . 44
B.1 Definition of decibel . 44
B.2 Conversion of relative uncertainties . 44
Bibliography . 45

Figure 1 – Typical spectral responsivity of photoelectric detectors . 14
Figure 2 – Example of a traceability chain . 16
Figure 3 – Measurement setup for sequential, fibre-based calibration . 19
Figure 4 – Change of conditions and uncertainty . 24
Figure 5 – Determining and recording an extension uncertainty . 30
Figure 6 – Possible subdivision of the optical reference plane into 10 × 10 squares, for
the measurement of the spatial response . 31
Figure 7 – Wavelength dependence of response due to Fabry-Perot type interference . 34
Figure 8 – Measurement setup of polarization dependent response . 35
Figure 9 – Nonlinearity calibration based on superposition . 36
Figure 10 – Measurement setup for nonlinearity calibration by comparison . 39

Table 1 – Calibration methods and correspondent typical power . 19
Table 2 – Nonlinearity . 38

– 4 – IEC 61315:2019 RLV © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CALIBRATION OF FIBRE-OPTIC POWER METERS

FOREWORD
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