  Certain intrinsic point defects in silicon carbide are promising quantum
systems with efficient spin-photon interface. Despite carbon vacancy in silicon
carbide is an elementary and relatively abundant intrinsic defect, no optical
signal has been reported associated with it. Here, we revisit the positively
charged carbon vacancy defects in the 4H polytype of silicon carbide (4H-SiC)
by means of \textit{ab initio} calculations. We find that the excited state is
optically active for the so-called h-site configuration of carbon vacancy in
4H-SiC, with zero-phonon line at $0.65~\mathrm{eV}$. We propose this defect as
an exotic paramagnetic near-infrared emitter in the IR-B region.
