ABSTRACT
This chapter reviews the exciting developments on candidate excitable semiconductor lasers and devices proposed in literature for a photonic spike processor. The semiconductor gain and absorber sections are isolated electrically with a proton implantation region, and a separate implant provides a smaller lifetime in the absorber section. Circular-cavity lasers are a class of semiconductor lasers that have also shown to exhibit dynamic excitability and have been investigated for application as a computational primitive. There has been exciting research on exploring excitability in periodic nanostructures called photonic crystals (PC). A PC is analogous to a semiconductor in that the propagation of photons is affected in the same way as the periodic potential in a semiconductor crystal influences the flow of electrons by defining allowed and forbidden electronic energy bands. A free-running single-mode semiconductor laser outputs stationary, coherent, continuous-wave light at a current pump rate the lasing threshold.
