A new paper published 27 September 2017 by ChAMP partners from Oxford and Exeter continues the search for new “neuromorphic computing” architectures that mimic the brain’s approach to simultaneous processing and storage of information is intense.
Figure shows A) Structure of neuron and synapse. Inset: Illustration of the synapse junction. (B) Schematic of the integrated photonic synapse resembling the function of the neural synapse. The synapse is based on a tapered waveguide (dark blue) with discrete PCM islands on top, optically connecting the presynaptic (pre-neuron) and the postsynaptic (post-neuron) signals. The red open circle is a circulator with port 2 and port 3 connecting the synapse and the post-neuron; weighting pulses are applied through port 1 to the synapse. (C) Optical microscope image of a device with the active region (red box) as the photonic synapse. The optical input to and output from the device are via apodized diffraction couplers (white boxes). Inset: A typical photonic chip containing 70 photonic synapses has a dimension smaller than a 5-pence coin. (D) Scanning electron microscope image of the active region of the photonic synapse corresponding to the red box in (C) with six GST units (1 μm × 3 μm, yellow, false-colored) on top of the waveguide (blue, false-colored). Inset: The zoomed-in tapered structure of the waveguide highlighted by the white dashed box.
see full paper at http://advances.sciencemag.org/content/3/9/e1700160