A pulse generator includes a pulse command register and a digital differential analyzer. The OPO uses bismuth triborate, BiB3O6 or a substituted form thereof, in collinear critical phase-matching as the nonlinear gain crystal. Phase errors caused by a nonlinear platform motion are compensated by controlling the phase offset between the illumination beam and the reference beam used to write the hologram based on inertial measurements of the flight path and the sensor line-of-sight pointing angles. The stored photon is then known to be circulating in the loop, and can be switched out of the loop at a later time chosen by the user, providing a single photon for potential use in a variety of quantum information processing applications.