APS -APS March Meeting 2017 - Event - Spectral tuning of optical coupling between air-mode nanobeam cavities and individual carbon nanotubes

摘要

Air-mode nanobeam cavities allow for high efficiency coupling to air-suspended carbon nanotubes due to their unique mode profile that has large electric fields in airfootnote{R. Miura, S. Imamura, R. Ohta, A. Ishii, X. Liu, T. Shimada, S. Iwamoto, Y. Arakawa, and Y. K. Kato, {it Nature Commun.} {f 5}, 5580 (2014).}. Here we utilize heating-induced energy shift of carbon nanotube emissionfootnote{P. Finnie, Y. Homma, and J. Lefebvre, {it Phys. Rev. Lett.} {f 94}, 247401 (2005).} to investigate the cavity quantum electrodynamics effects.In particular, we use laser-induced heating which causes a large blue-shift of the nanotube photoluminescence as the excitation power is increased.Combined with a slight red-shift of the cavity mode at high powers, detuning of nanotube emission from the cavity can be controlled.We estimate the spontaneous emission coupling factor $eta$ at different spectral overlaps and find an increase of $eta$ factor at small detunings, which is consistent with Purcell enhancement of nanotube emission.