  The negatively charged silicon vacancy center (SiV$^-$) in diamond is a
promising, yet underexplored candidate for single-spin quantum sensing at
sub-kelvin temperatures and tesla-range magnetic fields. A key ingredient for
such applications is the ability to perform all-optical, coherent addressing of
the electronic spin of near-surface SiV$^-$ centers. We present a robust and
scalable approach for creating individual, $\sim$50nm deep SiV$^-$ with
lifetime-limited optical linewidths in diamond nanopillars through an
easy-to-realize and persistent optical charge-stabilization scheme. The latter
is based on single, prolonged 445nm laser illumination that enables continuous
photoluminescence excitation spectroscopy, without the need for any further
charge stabilization or repumping. Our results constitute a key step towards
the use of near-surface, optically coherent SiV$^-$ for sensing under extreme
conditions, and offer a powerful approach for stabilizing the
charge-environment of diamond color centers for quantum technology
applications.
