Laser-ablated photonic microcavities for exciton and electron transport manipulation in organic dyes

Femtosecond laser technology is developing into a powerful and flexible tool for manufacturing polymeric photonic devices. Micro-nano precision is obtained by ultrafast laser ablation and minimal thermal damage to materials. Coupling optical microcavities of luminescent molecular materials have been a trending approach to advanced optical applications by harnessing light-matter interaction. Molecular materials with facile processibility are natural candidates with integrability, whilst nanocavity fabrication on these materials, partially for reproducible large-scale fabrication, is challenging. In this study, we use a femtosecond laser processing technique to ablate PMMA films doped with dye molecules to give high-quality Whispering-Gallery-Mode microcavity arrays with uniform morphology, vertical cavity wall, and no residue. Experimental and simulation studies suggest that the luminescence and electronic dipole properties of the material can be manipulated within microcavity diameters that determine the resonance wavelengths. The effectiveness of laser processing techniques is demonstrated in regulating the luminescence properties of optical materials for applications in nanophononics and optoelectronics.