BS EN 61744:2005

What is BS EN 61744- Calibration of fibre optic chromatic dispersion test sets about? 

BS EN 61744 provides standard procedures for the calibration of optical fibre chromatic dispersion (CD) test sets.  

BS EN 61744 also provides procedures to perform calibration checks on CD test sets whereby an extension to the test set calibration period may be obtained. 

BS EN 61744 defines a standard procedure for calibrating optical fibre chromatic dispersion (CD) test sets. The detailed calibration steps used vary according to the measurement technique used in the CD test set.  

BS EN 61744 specifies the procedures that can be applied to calibration laboratories and to the manufacturers or users of CD test sets for the purpose of: 

• Calibrating CD test sets 
• Setting specifications of CD test sets 
• Extending the calibration period of an already calibrated CD test set 

Note 1: Whilst it is acknowledged that chromatic dispersion also occurs in multimode fibre and this fibre may be measured on many CD test sets, BS EN 61744 will restrict discussion to single mode fibre measurements only. 

Note 2: BS EN 61744 is applicable to all types of CD test sets, with the exception that measurements on multimode optical fibres are excluded. 

Who is BS EN 61744- Calibration of fibre optic chromatic dispersion test sets for?  

BS EN 61744 on the calibration of fibre optic chromatic dispersion test sets is relevant to: 

• Manufacturers of optic chromatic dispersion test sets  
• Calibrators of optic chromatic dispersion 
• Fibre optic technicians 
• Fibre optic installers 
• Regulatory authorities 
• Testing authorities of chromatic dispersion 

Why should you use BS EN 61744- Calibration of fibre optic chromatic dispersion test sets? 

Chromatic dispersion is the variation with optical light wavelength of the light propagation delay time in a length of the fibre. This variation can cause bandwidth limitation in the fibre when used to transmit communication signals.  

Chromatic dispersion (CD) test sets are used to measure the chromatic dispersion properties of optical fibres and typically comprise an optical source of known wavelength(s), a fibre light input coupling and output coupling means optical detection means and electronic or optical means of determining the optical delay or dispersion at the source wavelength. BS EN 61744 describes the detailed procedures used to establish calibration of a CD test set. This is done by applying known artefacts or standards to the CD test set, measuring its response, and adjusting (correcting) the CD test set to achieve results that match the standards used.  

Thus, BS EN 61744 explains the way to bring CD test set results close to an agreement with other CD test sets also calibrated in a standardized manner. The requirement to calibrate the CD test set, traceable to known standards, is essential in order to help users with quality control in fibre optic production, fibre research and similar activities. The purpose of the procedures outlined in BS EN 61744 is to focus manufacturers and users of CD test sets on the reduction of measurement uncertainty in chromatic dispersion determination in optical fibres under all applicable conditions.