  Single photons of subnatural linewidth and high spectral brightness are
necessary for efficient light-matter interaction at the single photon level,
which lies at the heart of many quantum photonic technologies. Here we
demonstrate a bright source of single photons with subnatural linewidth,
controllable waveforms, and a high spectral brightness of $3.67 \times 10^5$
s$^{-1}$mW$^{-1}$MHz$^{-1}$. The interaction between the single photons and
atoms is demonstrated by the controlled absorption of the single photons in an
atomic vapor. Our work has potential applications in quantum information
technologies.
