No abstract

Optical injection locking has been demonstrated as an effective filter for optical communications. These optical filters have advantages over conventional passive filters, as they can be used on active material, allowing them to be monolithically integrated onto an optical circuit. We present an experimental and theoretical study of the optical suppression in injection locked Fabry–Pérot and slotted Fabry–Pérot lasers. We consider both single frequency and optical comb injection. Our model is then used to demonstrate that improving the Q factor of devices increases the suppression obtained when injecting optical combs. We show that increasing the Q factor while fixing the device pump rate relative to threshold causes the locking range of these demultiplexers to asymptotically approach a constant value.

We investigate the dynamics of asymmetrically coupled semiconductor lasers on photonic integrated circuits in experiment and theory. The experimental observations are explained using a rate-equation model for coupled lasers incorporating a saturable coupling waveguide. We perform a bifurcation analysis of the coupled laser dynamics, focusing on the effects of the coupling phase and the dynamical difference between passive and saturable coupling waveguides. For a passive waveguide, we find a bifurcation scenario closely resembling the well-known optical injection setup, which is largely insensitive to the coupling phase. When the coupling waveguide is saturable, the dynamics become increasingly complex and unpredictable, with a strong phase-dependence. Our results show the possibility of a simple layout for reproducible laser dynamics on a chip.

We model the situation of two lasers in a face-to-face arrangement, optically coupled through an attenuating element, where the distance between the lasers is on a scale typical in photonic integration (hundreds of micrometers to millimeters). We account for the existence of a frequency difference between the two single-mode lasers. Modified versions of the Lang-Kobayashi equations were employed to describe the interaction. By solving this delay differential equation system, we characterized different dynamical regimes including one- and two-color states and self-pulsations. We focus on the effect varying coupling strength and detuning between the lasers has on the frequencies of the lasers. Using the results of this frequency study, we identify the bifurcations causing changes between the different frequency regimes.