ABSTRACT
A spiking laser can be viewed as a neuron only in the context of a network. The configurable analog connection strengths between neurons, called weights, are as important to the task of network processing as the dynamical behavior of individual elements. Weight configuration happens on timescales much slower than network dynamics. This chapter deals with broadcast-and-weight as a wavelength-division multiplexing (WDM) protocol in which many signals can coexist in a single waveguide and all nodes have access to all the signals. The generated photocurrent modulates a nonlinear processor, which also serves as an electronic-optical converter. Photodetectors output a current that represents total optical power, thus computing the weighted sum of WDM inputs in the process of transducing them to an electronic signal, which is capable of modulating a laser device. Design parameters that impact network structure fundamentally exceed pure communication theory and must invoke theories of distributed computation, such as functional neural networks and/or cortical organization.
