  The implementation of non-classical light sources is becoming increasingly
important for various quantum applications. A particularly interesting approach
is to integrate such functionalities on a single chip as this could pave the
way towards fully scalable quantum photonic devices. Several approaches using
dielectric systems have been investigated in the past. However, it is still not
understood how on-chip nanoplasmonic antennas, interacting with a single
quantum emitter, affect the quantum statistics of photons reflected or
transmitted in the guided mode of a waveguide. Here we investigate a quantum
photonic platform consisting of an evanescently coupled nanoplasmonic
cavity-emitter system and discuss the requirements for non-classical light
generation. We develop an analytical model that incorporates quenching due to
the nanoplasmonic cavity to predict the quantum statistics of the transmitted
and reflected guided waveguide light under weak coherent pumping. The
analytical predictions match numerical simulations based on a master equation
approach. It is moreover shown that for resonant excitation the degree of
anti-bunching in transmission is maximized for an optimal cavity modal volume
$V_{c}$ and cavity-emitter distance $s$. In reflection, perfectly anti-bunched
light can only be obtained for specific $(V_{c},s)$ combinations. Finally, our
model also applies to dielectric cavities and as such can guide future efforts
in the design and development of on-chip non-classical light sources using
dielectric and nanoplasmonic cavity-emitter systems.
