Contagious photons: Laser dynamics and the susceptible-infected-recovered model.

Kozyreff, Gregory; Erneux, Thomas · Phys Rev E · 2023

basic_science · Level V

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Abstract

We explore a complete analogy between the classic susceptible-infected-recovered epidemiological model with natural birth and death rates, and class-B laser equations. As a result, recently derived asymptotic formulas in the former context can be used to describe the switch-on intensity pulse of a laser suddenly brought well above the lasing threshold, as in active Q-switching. Conversely, the well-studied laser relaxation oscillations find a companion behavior in epidemiology, emphasizing nontrivial timescales. Finally, we discuss the possible correspondence between multistrain outbreaks and multimode lasing.