Phase-locked lasing in 1D and 2D patterned metal-organic microcavities

Organic microcavities provide unique properties that are highly advantageous for designing microlasers, but lack in efficient ways to directly integrate electrodes able to drive high currents. The introduction of thin, patterned metal films, leading to the formation of local Tamm plasmon polariton states, has been recently demonstrated as a possible route to preserving coherence in the presence of significant optical loss. Here, periodic micron‐scale gratings of silver are embedded into a high‐quality organic microcavity, creating a crystal‐like photonic potential structure. Despite strong absorption of metallic layers, these structures readily lase upon optical excitation. In that case, the above threshold emission originates not from isolate metal‐free areas but instead from phase‐locked supermodes spreading over several grating periods. Remarkably, in‐plane coherence can spread even further when decreasing the grating period, covering distances of more than 50 μm and more than ten metal stripes. 1D and 2D gratings with varying periods are investigated using tomographic scanning of the k‐space emission fine structure, which exhibits a strong dependence on the grating geometry. These results support the fabrication of highly customizable organic microlasers with tailored in‐plane coherence, and demonstrate the coexistence of extended coherence and optical loss.