Device and a method for transforming signal propagation mode by interference

摘要

An optical device (D) is dedicated to transforming the propagation mode of optical signals. The device comprises mode transformation means ( 3-5 ) associated with a multimode fiber ( 2 ) and comprising first and second mode converters ( 3 and 5 ) coupled to each other by a multimode fiber portion ( 4 ) of selected length (L). The first converter ( 3 ) is fed with signals propagating in a first mode and it delivers the signals to the fiber portion ( 4 ) in part in the first mode and in part in a second mode of order higher than the first, and the second converter ( 5 ) is arranged to cause the signals in the first and second modes to interfere so that on outlet therefrom they present a selected spectral spacing.