  Single-Wall Carbon Nanotubes (SWNTs) are among the very few candidates for
single-photon sources operating in the telecom bands since they exhibit large
photon antibunching up to room temperature. However, coupling a nanotube to a
photonic structure is highly challenging because of the random location and
emission wavelength in the growth process. Here, we demonstrate the realization
of a widely tunable single-photon source by using a carbon nanotube inserted in
an original repositionable fiber micro-cavity : we fully characterize the
emitter in the free-space and subsequently form the cavity around the nanotube.
This brings an invaluable insight into the emergence of quantum
electrodynamical effects. We observe an efficient funneling of the emission
into the cavity mode with a strong sub-Poissonian statistics together with an
up to 6-fold Purcell enhancement factor. By exploiting the cavity feeding
effect on the phonon wings, we locked the single-photon emission at the cavity
frequency over a 4~THz-wide band while keeping the mode width below 80~GHz.
This paves the way to multiplexing and multiple qubit coupling.
