A fully solution-processed organic microcavity laser in the strong light-matter coupling regime.

Solid-state semiconductor lasers underpin technologies from telecommunications and data storage to sensing, medical diagnostics, and emerging quantum communication. Polaritons, hybrid exciton-photon states, have further extended this reach by enabling room-temperature effects such as low-threshold lasing and strong optical nonlinearities. Organic semiconductors are attractive for polaritonics because of their large exciton binding energies, strong nonlinearities, and compatibility with solution processing. However, while solution-processed organic films have been widely explored, the optical cavities used for organic polariton lasing have typically relied on vacuum deposition, limiting truly scalable, low-cost, and accessible device fabrication. Here, we show that all-dielectric organic microcavities fabricated entirely by solution processing, including both the mirrors and active layer, operate in the strong coupling regime, exhibit polariton lasing, and support reversible, detuning-dependent redistribution of the condensate at high excitation densities, establishing an accessible and tunable platform for nonlinear organic polariton physics.