Reconfigurable all-solid-state topological lasing at arbitrary sites

Topological lasers have emerged as a promising platform for robust photonic systems, yet current implementations relying on semiconductor microcavities and resonators suffer from fundamental constraints including low optical gain, limited output power and fixed lasing sites. To address these challenges, we present an all-solid-state, reconfigurable topological laser based on a Su-Schrieffer-Heeger waveguide array platform, fabricated in disordered laser crystal (Nd:BaLaGa3O7). Harnessing the high gain provided by solid-state lasers, we experimentally and theoretically demonstrate single-mode, continuous-wave topological lasing with output power surpassing 100 mW. In addition to conventional topological edge lasing, we observe topological lasing at trivial lattice terminations and reconfigurable interface sites at arbitrary lattice positions. This unconventional behavior arises from the non-Hermitian parity-time symmetry transition in subsystem at elevated pump power. Our work demonstrates on-demand, site-selectable topological lasing, offering both fundamental insights into topological phase transitions in non-Hermitian systems and practical opportunities to develop robust, reconfigurable topological photonic devices for advanced lasing and optical information processing. Topological lasers usually emit light from a fixed spot. Here, authors report on an all-solid-state platform where topological lasing is demonstrated at trivial lattice terminations as well as at reconfigurable arbitrary sites. The device consists of a Su-Schrieffer-Heeger waveguide array, printed in a disordered Nd:BaLaGa₃O₇ crystal.