  A recently proposed device, dubbed half-Josephson laser, provides a
phase-lock between the optical phase and the superconducting phase difference
between the leads of the device. In this paper we propose to utilize this
phase-lock for stabilization of voltage fluctuations, by two optical feedback
schemes. The first scheme involves a single half-Josephson laser and allows to
significantly decrease the diffusion coefficient of the superconducting phase
difference. The second scheme involves a stable optical source and a
fluctuating half-Josephson laser and permits quenching of the diffusion of the
relative phase of the lasers. This opens up perspectives of the optical control
of the superconducting phase and voltage fluctuations.
