Spiking neurons represent the most accurate model
of the neural cells by using pulses and timing for information
processing and adaptation. Visible light communication can be
leveraged to establish a wireless link between neurons in spiking
networks even when neural areas are in relative motions.
Typically, parallel transmission in electro-optical spiking neural
networks is performed using wavelength division multiplexing,
which is limited by the number of wavelengths used and
multiple bandpass optical filters. This paper explores the
possibility of using multi-level pulse amplitude modulation
(PAM) in multi-input-optical-axons (MIOA) integrated by the
parallel neural paths in a spiking neuron network (SNN). To
evaluate PAM-MIOA, we implement an electro-optical SNN
that controls the force of two anthropomorphic fingers actuated
by the shape memory alloy (SMA)-based actuators. The voltage
threshold level in PAM is automatically adjusted based on the
reference optical power. Results show that the electro-optical
SNN is able to hold an object when using PAM-MIOA even with
the link misalignment.