Characterization of High Speed Optical Detectors for Purpose of OM4 Fibre Qualification: Selective Mode Detection

The most important characterization of OM4 fibre is the ‘Differential Mode Delay’ (DMD) measurement. The measured DMD profile is some kind of ‘roadmap’ of the OM4 fibre; it contains all relevant data from which the main optical parameters are computed (for instance ‘Effective Modal Bandwidth’). Most requirements for the measurement equipment are well defined within standardization documents. However the requirements for the detector are still under discussion. This paper shows the state of the art of commercially available detectors (high speed optical electrical converters, fibre coupled) from different manufacturers. A method to characterize these detectors is suggested, and it shows the ‘ideal’ detector is not yet commercially available.