Adhyyan S. Mansukhani

Organic molecules embedded in an organic matrix exhibit lifetime-limited optical coherence and bright emission at cryogenic temperatures below 3 K. Here, we present a simple vapor-phase growth method for synthesizing optically thin DBT-doped anthracene crystals that are compatible with integrated nanophotonics. The crystals are 200 nm thick with sub-nm surface roughness and a tunable lateral dimension of up to 200 μm. The molecular transitions remain narrow and spectrally stable, with inhomogeneous broadening below 100 GHz, comparable to DBT in bulk anthracene. The dopant density is tunable up to several hundred molecules per μm2, ensuring emitters within the near-field of nanophotonic structures. We demonstrate that the crystals can be micropositioned onto integrated photonic devices with the molecular dipole aligned to the optical mode. This approach opens a path toward on-chip single-photon sources and collective many-emitter effects.

We present a hybrid solid-state cavity quantum electrodynamics (QED) platform that integrates a high density of coherent organic molecules with high-quality-factor nanophotonics. Thin anthracene crystals doped with dibenzoterrylene (DBT) are mechanically transferred onto prefabricated silicon nitride photonic crystal cavities, preserving both the cavity quality and molecular coherence. This approach decouples emitter synthesis from nanofabrication, providing a pathway for integrating other types of emitters. The high density of molecular emitters results in up to ten molecules being coupled to a single cavity. By tuning pairs of molecules into resonance within a single cavity mode, we observe cavity-mediated interactions in both dispersive and dissipative regimes. These results establish an accessible route to deterministic on-chip single- and multiphoton sources.