Quantum electrodynamics in photonic crystals

Kazuaki Sakoda

Ke Xu, Ming Fang, Jian Fen +3 more

An electrodynamic model is presented in this Letter to describe thresholdless lasers, utilizing the application of photonic time crystals (PTCs). By integrating the distinctive physical properties of PTCs and employing a comprehensive model based on a four-level system, the feasibility of achieving thresholdless laser operation is demonstrated. The proposed electrodynamic model comprehensively captures the intricate interplay between the electromagnetic field and the PTC medium. The model takes into account the ultrafast periodic variations in the refractive index of the PTCs, which arise from their time crystal-like behavior. Additionally, the dynamic response of the four-level system is considered, factoring in the processes of population inversion and relaxation. This Letter seeks to elucidate the underlying mechanisms that facilitate thresholdless laser operation in PTC-based systems. Through our electrodynamic modeling approach, we demonstrate that the ultrafast variations in the refractive index of PTCs give rise to a self-sustaining laser action, obviating the need for a lasing threshold. Moreover, we investigate the impact of various parameters, including pump power and modulation period, on the laser's performance and output characteristics. The developed electrodynamic model provides a comprehensive framework for comprehending and designing thresholdless lasers based on photonic time crystals. This research contributes to the advancement of thresholdless laser technology and opens up possibilities for applications in optical communications, sensing, and quantum photonics.

S. Gadde, John, Jelba, Elaganuru Bashaiah +1 more

We report the cavity quantum electrodynamics conditions using a composite photonic crystal symmetric cavity (CPCSC) on an optical nanocapillary fiber (NCF). The CPCSC is formed by combining the NCF and the symmetric defect mode nano-grating. The maximum channeling efficiency up to 87% is realized by placing the single quantum emitter at the anti-node position of the CPCSC. The current platform paves the way for manipulating single photons with applications in quantum technology.

Ke Xu, Ming Fang, Jian min Feng +4 more

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.

Valery I. Rupasov