Fabrication of an optoelectronic AlGaAs/GaAs waveguide neuron

A novel optical waveguide neuron is fabricated. It accepts two inputs, applies adjustable weights to them, sums the weighted inputs, and thresholds the sum to issue one output. An AlGaAs/GaAs p-i-n diode waveguide with a Wannier-Stark superlattice in the core is used. Two modulators and one saturable absorber are monolithically integrated on a 5- mu m rib waveguide Y-junction combiner. A simple self-aligned single-mask liftoff technique with wet chemical etching is used. At 780 nm the weights vary from 1 to -25 dB/mm for reverse bias below 7 V, and a 25-dB thresholding nonlinearity is obtained.<
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