Continuous‐Wave Pumped Perovskite Lasers with Device Area Below 1 µm²

Abstract Continuous‐wave (CW) pumped lasers with device areas below 1 µm² constitute a key step to meeting the energy efficiency requirement for on‐chip optical communications. However, a debate about whether a sub‐micrometer device size and low threshold can be simultaneously satisfied has persisted owing to insurmountable radiation losses when approaching the optical diffraction limit. Herein, a record‐small CW optically pumped perovskite laser with a device area of 0.65 µm² is demonstrated. The thresholds of sub‐micrometer lasers can be found lower than those of several‐micrometer counterparts, and are ascribed to the enlarged group refractive index and modal confinement resulting from the enhanced exciton–photon coupling. Moreover, the operation temperature is elevated to 150 K through the reduction in heat generation. These findings unveil the potential of exciton–polaritons in laser miniaturization, providing an alternative for developing low‐threshold semiconductor lasers without artificial optical cavities, to approach the optical diffraction limit.