  Engineering an array of precisely located cavity-coupled active media poses a
major experimental challenge in the field of hybrid integrated photonics. We
deterministically position solution processed colloidal quantum dots (QDs) on
high quality-factor silicon nitride nanobeam cavities and demonstrate
light-matter coupling. By lithographically defining a window on top of an
encapsulated cavity that is cladded in a polymer resist, and spin coating QD
solution, we can precisely control the placement of the QDs, which subsequently
couple to the cavity. We show that the number of QDs coupled to the cavity can
be controlled by the size of the window. Furthermore, we demonstrate Purcell
enhancement and saturable photoluminescence in this QD-cavity platform.
Finally, we deterministically position QDs on a photonic molecule and observe
QD-coupled cavity super-modes. Our results pave the way for controlling the
number of QDs coupled to a cavity by engineering the window size, and the QD
dimension, and will allow advanced studies in cavity enhanced single photon
emission, ultralow power nonlinear optics, and quantum many-body simulations
with interacting photons.

Optics;Quantum Physics