Integration of Semiconducting Carbon Nanotubes Within a Silicon Photonic Molecule

Integration of nanomaterials within optical nanocavities provides a unique potential for flexible control of light emitters properties by photonic band gap engineering and cavity Purcell effects. Here, we propose a one-dimensional heterostructure nanocavity exhibiting both non-coupled and coupled cavity modes, i.e. simultaneously acting as a single cavity and as a photonic molecule. The main cavity resonances are engineered to yield a wide spectral separation and for the first time to match the emission wavelengths of two different kinds of semiconducting single wall carbon nanotubes (s-SWNTs). By probing the photoluminescence (PL) from s-SWNTs coupled with the nano cavity modes, coupling of the s-SWNTs PL simultaneously into the several cavity modes is demonstrated. For modes governed by the photonic molecule behavior, the wavelength splitting of the two coupled modes is dominated by the cavity barrier width. The excitation of the bonding (B) and anti-bonding (AB) cavity modes then yields PL resonant enhancement that can be tuned by the pumping position and polarization filter. These results demonstrate the potential of the proposed multimode photonic molecule to tailor light-nanomaterial interactions on chip, paving the way for the development of tunable hybrid photonic circuits relying on nanoemitters in cavities for light generation purposes.