Mode filtering and mode selection for multimode optical fibre with core and envelope, which has periodic index structure with rising reflection capacity of envelope only for specified transversal mode

摘要

The multimode optical fibre has core and envelope, with latter containing periodic index structure, with increasing reflection capacity of envelope for specified transversal mode only. Thus only this transversal mode can propagate along optical fibre. For mode selection optical fibre cross-section has periodically variable refraction index structure, which permits only specified mode to propagate along optical fibre, with specified mode selected as desired mode only. An Independent claim is also included for optical fibre.