Few-mode fibers as optical dendrites for 40 Gbps computing

We show the computational power of few-mode fibers (FMF) in a 40 Gbps spatiotemporal coincidence detector scheme. We consider a 5.5 m step-index FMF, with a 16.6 mu m core diameter, as the medium that introduces various delays to a temporal input pulse, via the supported propagation fiber modes. In our representation, the different group velocities of the excited fiber modes define equivalent optical dendritic branches. A 1550 nm laser's optical output is modulated by a 40 Gbps binary sequence and coupled to the FMF. The output optical pattern is photodetected by a 3x3 array and used to solve successfully a 6-bit header classification task.