  We propose a new signaling scheme for on-chip optical-electrical-optical
artificial neural networks that utilizes orthogonal delay-division multiplexing
and pilot-tone based self-homodyne detection. This scheme offers a more
efficient scaling of the optical power budget with increasing network
complexity. Our simulations, based on a 220 nm SOI silicon photonics
technology, suggest that the network can support 31 x 31 neurons, with 961
links and freely programmable weights, using a single 500 mW optical comb and
an SNR of 21.3 dB per neuron. Moreover, it features a low sensitivity to
temperature fluctuations, ensuring that it can be operated outside of a
laboratory environment. We demonstrate the network's effectiveness in nonlinear
equalization tasks by training it to equalize a time-interleaved ADC
architecture, achieving an ENOB over 4 over the entire 75 GHz ADC bandwidth. We
anticipate that this network architecture will enable broadband and low latency
nonlinear signal processing in practical settings such as ultra-broadband data
converters and real-time control systems.
