Single-Mode Lasing with Spontaneous Symmetry Breaking from a Perovskite Microdisk Dimer

In this study, we design novel single-mode lasers based on non-Hermitian physics to avoid inadequate mode performance when the free spectral range is small. The perovskite microlaser, consisting of two partly fused microdisks, is presented here. Spontaneous symmetry breaking occurs under uniform pumping, which results in directional single-mode lasing at a visible range with an improved side-mode suppression ratio. In addition, a wide pump range becomes applicable due to microcavity property, where the single mode is stable even at 2.4 times the pumping threshold. The structural design with spontaneous symmetry breaking opens a new route to synthetic single-mode laser systems and other photonic devices at a visible range.