FIELD: physics.
SUBSTANCE: group of launched modes is determined. For that group of modes, a differential mode delay diagram is constructed and the refraction index profile of the multimode optical fibre is calculated. Differential mode delay values for that group of modes are minimal and the refraction index profile of the core is selected based on the condition of minimising the value
where 
is the value of group velocity of the j-th launched mode LPlm (j) in the multimode optical fibre; 
is the reference group velocity, relative which group velocities of launched modes LPlm are adjusted; M is the number of launched modes carrying the power of the multimode optical signal in the multimode optical fibre, for which the normalised amplitude is not less than 0.1.
EFFECT: high throughput and length of the multimode fibre optic transmission line.
5 dwg
