Hybrid plasmonic nano-emitters based on the combination of quantum dot emitters (QD) and plasmonic nanoantennas open up new perspectives in the control of light. However, precise positioning of any active medium at the nanoscale constitutes a challenge. Here, we report on the optimal overlap of antenna’s near-field and active medium whose spatial distribution is controlled via a plasmon-triggered 2-photon polymerization of a photosensitive formulation containing QDs. Au nanoparticles of various geometries are considered. The response of these hybrid nano-emitters is shown to be highly sensitive to the light polarization. Different light emission states are evidenced by photoluminescence measurements. These states correspond to polarization-sensitive nanoscale overlap between the exciting local field and the active medium distribution. The decrease of the QD concentration within the monomer formulation allows trapping of a single quantum dot in the vicinity of the Au particle. The latter objects show polarization-dependent switching in the single-photon regime.

A micrometric Fabry–Perot refractometer based on an end-of-fiber polymer tip is proposed. The fiber tip, with a length of $36\mu \text{m}$, was fabricated by self-guiding photopolymerization. The two-wave interferometric operation was achieved by combining the light waves generated at the interface between the single-mode fiber and the polymer tip, and at the fiber tip end (Fresnel reflection). The Fabry–Perot interferometer is coherence addressed and heterodyne interrogated, resulting into a liquid refractive index resolution of $\approx 7.5\times {10}^{-4}$.