BS EN 60793-1-43:2015
$142.49
Optical fibres – Measurement methods and test procedures. Numerical aperture measurement
| Published By | Publication Date | Number of Pages |
| BSI | 2015 | 24 |
This part of IEC 60793 establishes uniform requirements for measuring the numerical aperture of optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes.
The numerical aperture (NA) of categories A1, A2, A3 and A4 multimode fibre is an important parameter that describes a fibre’s light-gathering ability. It is used to predict launching efficiency, joint loss at splices, and micro/macrobending performance.
The numerical aperture is defined by measuring the far-field pattern (NA ff). In some cases the theoretical numerical aperture (NA th) is used in the literature, which can be determined from measuring the difference in refractive indexes between the core and cladding. Ideally these two methods should produce the same value.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 6 | CONTENTS |
| 8 | FOREWORD |
| 10 | 1 Scope 2 Normative references 3 Overview of method |
| 11 | 4 Reference test method Figures Figure 1 – Representative refractive index profile for a graded index multimode fibre |
| 12 | 5 Apparatus 5.1 Input system 5.1.1 Light source 5.1.2 Input optics 5.1.3 Fibre input end support and alignment 5.1.4 Cladding mode stripper 5.2 Output system and detection 5.2.1 General |
| 13 | 5.2.2 Technique 1 – Angular scan (see Figure 2) Figure 2 – Technique 1 – Angular scan |
| 14 | 5.2.3 Technique 2 – Angular scan (see Figure 3) 5.2.4 Technique 3 – Scan of the spatial field pattern (see Figure 4) Figure 3 –Technique 2 – Angular scan |
| 15 | Figure 4 – Technique 3 – Scan of the spatial field pattern |
| 16 | 5.2.5 Technique 4 – Inverse far-field measurement (see Figure 5, applicable to subcategory A4d fibres) |
| 17 | 6 Sampling and specimens 6.1 Specimen length 6.2 Specimen endface 7 Procedure 8 Calculations 8.1 Far-field versus maximum theoretical value Figure 5 – Technique 4 – Inverse far-field method |
| 18 | 8.2 Threshold intensity angle, θk 8.3 Numerical aperture, NAff Figure 6 – Example of a far-field NA measurement |
| 19 | 8.4 Calculating far-field intensity pattern when using Technique 3 8.5 Calculating NA when using Technique 4 9 Results 9.1 Information available with each measurement Figure 7 – Sample output of an A4d fibre measured using Technique 4 |
| 20 | 9.2 Information available upon request 10 Specification information |
| 21 | Annex A (informative)Mapping NA measurement to alternative lengths A.1 Introductory remark A.2 Mapping long length NAff measurement to short length NAff measurement |
| 22 | Annex B (normative)Product specific default values for NA measurement B.1 Introductory remark B.2 Table of default values used in NA measurement for multimode products Table B.1 – Default values for parameters used in the far-field NA measurement of multimode fibres |
Related products
-
BS EN 60793-1-43:2015 – TC:2020 Edition
Tracked Changes. Optical fibres – Measurement methods and test procedures. Numerical aperture measurement Published By…
