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COMPOSED MULTICORE OPTICAL FIBER DEVICE
WO20260381
Examples refer to a composed multicore optical fiber (MCF) device that comprises a first segment (MCF1) of a MCF comprising three coupled identical cores and having a first length (L1) and a second segment (MCF2) of the same MCF having a second length (L2). L1 and L2 are different from each other. One of the three coupled cores is located in a geometrical centre of the MCF. The first segment (MCF1) and the second segment (MCF2) of the MCF are rotated 180 degrees relative to each other and spliced together. The first segment (MCF1) of the MCF is spliced to a first segment (SMF1) of a single mode fiber (SMF) and the second segment (MCF2) of the MCF is spliced to a second segment (SMF2) of the SMF. The free end of the second segment (SMF2) of the SMF is coupled to a mirror (M) to reflect an optical signal coming from the first segment (SMF1) of the SMF.
The present invention is intended to overcome the problems of cascaded optical fiber interferometers by using MCFs with three coupled cores spliced between two segments of single mode optical fiber (SMF). The fundamental mode 20 transmitted through the SMF provokes the excitation of several modes in the MCFs, more particularly several supermodes, which in turn produces a periodic modulation of the spectral response of the device due to supermode interference or coupling in the MCFs. As generally used herein, supermodes may refer to modes that are supported by MCF in which the cores are close enough that the guided light can couple by evanescent interaction between the cores.