Nematicon-Assisted Mode Coupling to Optical Fibers

Through soliton excitation in a fiber integrated nematic liquid crystals cell, we demonstrated an all-optical response and electrical tunable structure for light coupling and mode conversion in few mode fibers. The light is guided and controlled from the transmitting to the receiving end, making use of the soliton induced waveguide channel, the so called self-guided effect. Both a near-infrared laser, i.e., signal light, and a visible laser, i.e., the probe light, are introduced to demonstrate the self-guided effect and mode conversion, which results match well theoretically and experimentally. Our results show that, the transmitting light can be guided and selectively coupled into lower or higher order modes of the receiving fiber by steering its ‘walk-off’ through voltage control. Besides, the proposed mode converting operation can work in both the polarization-mixed and polarization-separated regimes, and is realizable in a remarkably wide wavelength band.