Exploring cavity soliton trapping with egg-carton potentials

Cavity solitons (CSs) are promising candidates for future information technology applications, including optical frequency comb generation and optical memory devices. However, their control, particularly trapping, remains challenging and has only been rarely demonstrated. In this work, we explore the possibility of trapping CSs using two variants of an egg-carton potential: multiplicative and additive cosine potentials. The study is conducted within the nonlinear microcavity of a vertical-cavity surface-emitting laser (VCSEL) incorporating a graphene saturable absorber and frequency-selective feedback. The intracavity field dynamics is governed by the complex Ginzburg–Landau equation, which is solved numerically using the split-step Fourier method. Initial seed values are determined from the CS stability domain, obtained analytically through the Lagrangian variational method combined with the Lyapunov stability criterion. Stable CSs exist only within a limited range of system parameters. In the absence of external potentials, CSs typically exhibit free motion; however, with the proposed potential variants, successful trapping is achieved, predominantly near the central maxima of the potential landscape. These findings offer more insights into soliton confinement in nonlinear microcavities and may pave the way for practical implementations in advanced photonic devices.