Attenuation Reference Fibre
The artefact consists of a length (usually 13 km for single-mode fibre, 4.4 km for multimode fibre) wound on a standard shipping reel. The attenuation is measured using the internationally recognised reference test method; the cut-back technique. This technique compares the power transmitted through a very short length of fibre to that transmitted through the entire length of the fibre under test.
Fibre types that can be supplied include:
- Matched Clad - Standard or SMF28 fibre
- Dispersion shifted fibre
- 50/125 µm multimode fibre
- 62.5/125 µm multimode fibre
Other lengths of fibre and different fibre types can be provided on request.
The graph above shows a typical plot of total attenuation as a function of wavelength for single mode fibre.
The optical length of the fibres can also be calibrated, and if connectors are fitted to the fibre, they can be used to calibrate OTDR's.
A copy of a typical Calibration Certificate is available to download.
Optical Characteristics
| Fibre Type | Measurement range | Attenuation (dB/km) | Typical measurement uncertainty |
| Single mode | 1200 to 1650 nm | 0.34 (@ 1310 nm) 0.19 (@ 1550 nm) |
± 0.03 dB |
| 50/125 µm Multimode fibre | 800 to 900 nm 1250 to 1350 nm |
≤ 2.5 dB/km ≤ 0.7 dB/km |
± 0.06 dB |
Contact
Customer Service tel: +44 20 8943 8637
E-mail: fibreoptics_enquiries@npl.co.uk