Photostable Molecules on Chip: Integrated Sources of Nonclassical Light

The on-chip integration of quantum
light sources and nonlinear elements constitutes a major step toward
scalable photon-based quantum information processing and communication.
In this work we demonstrate the potential of a hybrid technology that
combines organic-molecule-based quantum emitters and dielectric chips
consisting of ridge waveguides and grating far-field couplers. In
particular, dibenzoterrylene molecules in thin anthracene crystals
are used as single-photon sources, exhibiting long-term photostability,
easy fabrication methods, almost unitary quantum yield, and lifetime-limited
emission at cryogenic temperatures. We couple such single emitters
to silicon nitride ridge waveguides, showing a coupling efficiency
of up to 42 ± 2% over both propagation directions. Our results
open a novel path toward a fully integrated and scalable photon-processing
platform.