Thresholdless Laser Based on Photonic Time Crystals

Abstract

Abstract We present an electrodynamic model for thresholdless lasers based on the utilization of photonic time crystals (PTCs). By incorporating the unique physical properties of PTCs and employing a comprehensive four-level system model, we demonstrate the feasibility of achieving thresholdless laser operation. The proposed electrodynamic model captures the intricate interplay between the electromagnetic field and the PTC medium. We account for the ultrafast periodic variations in the refractive index of the PTCs, which are a result of their time crystal-like behavior. The model considers the dynamic response of the four-level system, taking into account the population inversion and relaxation processes. Through our electrodynamic modeling, we elucidate the underlying mechanisms that enable thresholdless laser operation in PTC-based systems. We demonstrate that the ultrafast refractive index variations lead to a self-sustaining laser action, eliminating the need for a lasing threshold. Moreover, we investigate the influence of various parameters, such as pump power and modulation period, on the laser performance and output characteristics. The electrodynamic model developed in this study provides a comprehensive framework for understanding and designing thresholdless lasers based on photonic time crystals. Our work contributes to the advancement of thresholdless laser technology and paves the way for potential applications in areas such as optical communications, sensing, and quantum photonics.