Characterization of High Speed Optical Detectors for Purpose of OM4 Fibre Qualification: Selective Mode Detection Topics: Fiber Optics devices; Fiber Optics Technology; Optical Communications and Networking; Optical Instrumentation In Proceedings of the 6th International Conference on Photonics, Optics and Laser Technology PHOTOPTICS - Volume 1, 141-147, 2018 , Funchal, Madeira, Portugal