Proceedings Article | 18 September 2018
Proc. SPIE. 10734, Quantum Nanophotonics 2018
KEYWORDS: Plasmonics, Single photon, Photonics, Optical resonators, Aluminum, Antennas, Quantum information, Quantum information processing, Light
Strong interaction between light and a single quantum emitter is pivotal to many applications, including single photon sources and quantum information processing. Typically, plasmonic antennas or optical cavities are used to boost this interaction. The former can focus light in a deeply subwavelength region, whereas the latter can store light for up to billions of oscillations.
In our work, we combine these two opposite elements into a single coupled system. First, we show theoretically [1] that hybrid cavity-antenna systems can achieve Purcell enhancements far exceeding those of the bare cavity and antenna, and can do so at any desired bandwidth. This requires a delicate balance between spoiling the cavity with the antenna on the one hand, and cooperative and interference effects on the other.
We then present our experimental results on hybrid systems using a whispering-gallery mode cavity and an aluminum plasmonic antenna. Using taper-coupled excitation of the hybrid mode, we study quality factors and radiation patterns, demonstrating that we can control the antenna-cavity coupling strength by varying their respective frequency detuning. We show that we can achieve modes that retain quality factors around 10^4, while creating a strongly localized field around the antenna. As such, we can exploit the benefits of plasmonic confinement without suffering from the usual losses. Finally, we present first studies of fluorescent emitters coupled to the hybrid modes.
[1] Doeleman, H. M., Verhagen, E., & Koenderink, A. F., "Antenna–Cavity Hybrids: Matching Polar Opposites for Purcell Enhancements at Any Linewidth." ACS Photonics 3.10 (2016): 1943-1951.
