  A key challenge for the realization of future skyrmion devices comprises the
controlled creation, annihilation and detection of these topologically
non-trivial magnetic spin textures. In this study, we report an all-optical
approach for writing, deleting, and reading skyrmions in the cubic chiral
magnet Fe$_{0.25}$Co$_{0.75}$Si based on thermal quenching. Using focused
femtosecond laser pulses, patches of a skyrmion state are created and
annihilated locally, demonstrating unprecedented control of thermally
metastable skyrmions in a bulk compound. The skyrmion state is read-out by
analyzing the microwave spin excitations in time-resolved magneto-optical Kerr
effect measurements. Extracting the magnetic field and laser fluence
dependence, we find well-separated magnetic field regimes and different laser
fluence thresholds for the laser-induced creation and annihilation of
metastable skyrmions. The all-optical skyrmion control, as established in this
study for a model system, represents a promising and energy-efficient approach
for the realization of skyrmions as magnetic bits in future storage devices,
reminiscent of magneto-optical storage devices in the past.
