A two-dimensional organic-exciton polariton lattice fabricated using laser patterning

Exciton-polaritons in 2D lattice geometries now attract considerable attention as systems in which to explore new physics. However, such structures are relatively difficult to fabricate as this can involve sophisticated milling or etching of cavity layers to create arrays of defects. Here, a straightforward technique is reported that allows rapid fabrication of 2D polariton lattices that operate at room temperature. Specifically, laser patterning has been used to write a 2D square lattice of defects into a sacrificial polymer layer. An organic microcavity structure is then built on top of the patterned polymer, with the morphology of the patterned polymer propagating through the subsequent layers and spatially modifying the optical path-length of the active cavity region. Using real- and momentum-space spectroscopy, the formation of gapped polaritonic band structures has been demonstrated at room temperature. The optical writing approach discussed here opens up the way for fabrication of more complex 2D-lattice geometries for studying topological physics at room temperature.