Optical neural network

<p>An optical neural network is a physical implementation of an <a href="/facts/Artificial_neural_network/6V1jMlkx">artificial neural network</a>  with <a href="/facts/Photonics/6UHcPXbq">optical components</a>.  Early optical neural networks used a photorefractive <a href="/facts/Volume_hologram/06zMGwee">Volume hologram</a> to interconnect arrays of input neurons to arrays of output with synaptic weights in proportion to the multiplexed hologram's strength.  Volume holograms were further multiplexed using spectral hole burning to add one dimension of wavelength to space to achieve four dimensional interconnects of two dimensional arrays of neural inputs and outputs.  This research led to extensive research on alternative methods using the strength of the optical interconnect for implementing neuronal communications.
</p><p>Some artificial neural networks that have been implemented as optical neural networks include the <a href="/facts/Hopfield_neural_network/xUBr6rpm">Hopfield neural network</a> and the Kohonen <a href="/facts/Self-organizing_map/uuMRbpkl">self-organizing map</a> with <a href="/facts/Liquid_crystal/ehCCST89">liquid crystal</a> spatial light modulators  Optical neural networks can also be based on the principles of <a href="/facts/Neuromorphic_engineering/REplYB5e">neuromorphic engineering</a>, creating neuromorphic photonic systems. Typically, these systems encode information in the networks using spikes, mimicking the functionality of <a href="/facts/Spiking_neural_network/DeT3wPPV">spiking neural networks</a> in optical and photonic hardware. Photonic devices that have demonstrated neuromorphic functionalities include (among others) <a href="/facts/Vertical-cavity_surface-emitting_laser/D2KKahPJ">vertical-cavity surface-emitting lasers</a>, integrated photonic modulators, optoelectronic systems based on <a href="/facts/Superconductivity/pqQAlSzJ">superconducting</a> <a href="/facts/Josephson_effect/2fvcdS8N">Josephson junctions</a> or systems based on <a href="/facts/Resonant-tunneling_diode/Fl58cmhJ">resonant tunnelling diodes</a>.
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Optical neural network open-in-new

Optical neural network