Nanoring Tamm cavity in the telecommunications O band

Quantum and classical telecommunications require efficient sources of light. Semiconductor sources, owing to the high refractive index of the
medium, often exploit photonic cavities to enhance the external emission of photons into a well-defined optical mode. Optical Tamm States
(OTSs) in which light is confined between a distributed Bragg reflector and a thin metal layer have attracted interest as confined Tamm structures are readily manufactureable broadband cavities. Their efficiency is limited however by the absorption inherent in the metal layer. We
propose a nanoring Tamm structure in which a nanoscale patterned annular metasurface is exploited to reduce this absorption and thereby
enhance emission efficiency. To this end, we present designs for a nanoring Tamm structure optimized for the telecommunications O band
and demonstrate a near doubling of output efficiency (35%) over an analogous solid disk confined Tamm structure (18%). Simulations of
designs optimized for different wavelengths are suggestive of annular coupling between the Tamm state and surface plasmons. These designs
are applicable to the design of single photon sources, nano-LEDs, and nanolasers for communications.