All-optical switching devices are crucial to realize optical computers which offer ultra-fast information processing. To date, many switching concepts have been investigated, but most suffer from speed, efficiency, reliability, size and cost limitations. Optivision, Inc. proposes to design, fabricate and evaluate a novel all-optical switching device based on nonlinear bimodal fiber-optic interferometry using LP01-LP02 modes. A bimodal polymer fiber (BPF) is spliced through two bi-tapers between two single mode fibers (SMFs). The field access for high sensitivity to the polymer refractive index is the particular bi- tapers to be exploited. This results in a coupling-beating- coupling structure in the SMF/BPF/SMF arrangement with the beating of LP01-LP02 modes optically controlled by a Kerr-like nonlinear polymer. The Kerr-induced nonlinear differential phase shift in the BPF controls the optical coupling at the BPF/SMF interface. The fabricated switch will be configured as a building block for logic gate operations. Using fiber-optic amplifiers, these all-fiber logic gates can be cascaded and have large fan- out. In addition, they will be fast, compact, with low power consumption and low cost, and are compatible with the fiber optic networks of the future advanced photonic communication and computer designs to satisfy expected heavy demand on the information handling capacity.
