TEP Seminar - Qihua Xiong

Optical microcavities are photonic structures that confine light within wavelength-scale volumes, such as distributed Bragg reflectors, photonic crystals, microspheres, or ring resonators. They offer versatile platform to investigate and manipulate light-matter interactions. In the weak-coupling regime, the spontaneous emission rate will be modulated by the Purcell effect, facilitating technological applications in low-threshold lasers, efficient nonlinear processes, and ultra-sensitive biosensors. In the strong-coupling regime, a quantum superposition between photonic state and matter-wave excitation will be resulted, enabling diverse quantum information applications. In this talk, we will discuss our recent effort in manipulating exciton polariton condensates at room temperature in halide perovskite or two-dimensional semiconductor microcavities. We discuss how we can use optical lattices to engineer the strong optical responses including topological properties, and their ultrafast propagation. Finally, we will briefly discuss the strong nonlinear interactions in polaritons which drives coherent long-range propagation, manifested as optical spin Hall effect and ultrafast functional polaritonic devices. The future directions towards room-temperature polaritonics will be discussed in a perspective way.