BS EN 60793-1-45. Optical fibres. Part 1-45. Measurement methods. Mode field diameter measurement Optical fibres, Fibre optics, Optical communication systems, Fibre optic cables, Electronic equipment & components, Optical measurement, Test methods, Temperature measurement, Environmental testing, Electric field effects, Magnetic field effects, Magnetic field strength, Electromagnetic fields, Electromagnetic radiation, Electrical wave measurement, Transverse waves, Diameter, Homogeneity, Test equipment, Mathematical calculations, Formulae (mathematics)