31 January 2024 | Weijie Liu, Quancheng Liu, Xiang Ni, Yuechen Jia, Klaus Ziegler, Andrea Alù, Feng Chen
This paper explores the application of Floquet parity-time (PT) symmetry in integrated photonics, a field that has gained significant attention for its potential in lasing, sensing, and enhanced light-matter interactions. Traditional PT-symmetric systems require large levels of gain and loss, posing practical challenges. Floquet PT-symmetry, achieved by periodically flipping the effective gain/loss distribution in time, relaxes these requirements and allows for precise control over the exceptional point (EP) and PT-symmetry phases through modulation period. The authors demonstrate this concept in an integrated photonic waveguide platform, where the role of time is replaced by the propagation direction. They experimentally show spontaneous PT-symmetry breaking at small gain/loss levels and efficient control of amplification and suppression through the excitation ports. This work introduces the advantages of Floquet PT-symmetry in practical integrated photonic settings, enabling advanced manipulation and control of light propagation, with potential applications in nano-photonics and coherent control of nanoscale light amplification and routing. The study highlights the ability to tailor phase transitions and amplification regimes through the modulation period, providing a powerful platform for observing and leveraging PT-symmetric phenomena.This paper explores the application of Floquet parity-time (PT) symmetry in integrated photonics, a field that has gained significant attention for its potential in lasing, sensing, and enhanced light-matter interactions. Traditional PT-symmetric systems require large levels of gain and loss, posing practical challenges. Floquet PT-symmetry, achieved by periodically flipping the effective gain/loss distribution in time, relaxes these requirements and allows for precise control over the exceptional point (EP) and PT-symmetry phases through modulation period. The authors demonstrate this concept in an integrated photonic waveguide platform, where the role of time is replaced by the propagation direction. They experimentally show spontaneous PT-symmetry breaking at small gain/loss levels and efficient control of amplification and suppression through the excitation ports. This work introduces the advantages of Floquet PT-symmetry in practical integrated photonic settings, enabling advanced manipulation and control of light propagation, with potential applications in nano-photonics and coherent control of nanoscale light amplification and routing. The study highlights the ability to tailor phase transitions and amplification regimes through the modulation period, providing a powerful platform for observing and leveraging PT-symmetric phenomena.