Analysis of nonlinear optical-electromagnetic interactions in ultrafast mode-locked laser diodes

The operation of mode-locked (ML) semiconductor laser diodes (LDs), in common with lasers of other types, is a nonlinear process in which a balance of dispersion and various nonlinearities results in the generation of an ultrashort optical pulse, repeated at the cavity round-trip frequency or its harmonic and with parameters, averaged over a round-trip, constant, similar to an optical soliton. In this paper we theoretically analyse the fundamentals of high-frequency mode-locked laser diodes and their application to generating and/or frequency shifting ultrafast electrical signals.