Monolithically integrated multi-section semiconductor lasers: Towards the future of integrated microwave photonics

Abstract

Recent advances in monolithically integrated multi-section semiconductor lasers (MI-MSSLs) have propelled microwave photonic (MWP) technologies to new potentials with a compact, reliable, and green implementation. Much research has examined that MI-MSSLs can realize the same or even better MWP functions compared to discrete lasers by taking advantages of enhanced light–matter interactions. Here, we review these recent advances in this emerging field and discuss the corresponding photonic microwave applications. Three main kinds of MI-MSSL structures are demonstrated in general including passive feedback laser, active/amplified feedback laser, as well as monolithically integrated mutually injected semiconductor laser. The focus of this paper is on the MWP techniques based on the nonlinear dynamics of MI-MSSLs. The primary MWP applications considered in this paper cover from electro-optic conversion characteristics enhancement, photonic microwave generation, microwave photonic filter, to multi-wavelength laser array for wavelength division multiplexing radio-over-fiber (WDM-RoF) networks. Especially, the four special dynamic states of free-running oscillation, mode-beating self-pulsations (MB-SPs), period-one (P1) oscillation, and sideband injection locking are considered and demonstrated in detail for photonic microwave generation. We also take a look at the future prospects of the research directions and challenges in this area.