Phase-controlled absorption-gain properties and optical switching in nanodiamond nitrogen-vacancy center

We study phase-controlled absorption-gain and dynamic switching behaviors in a nanodiamond nitrogen-vacancy (NV) center. The NV center is driven coherently by a weak probe laser field, a control laser field and a microwave field. To describe the transient behavior of the system, we go beyond the steady-state approximation and simultaneously solve the coupled Bloch–Maxwell equations for the NV center and the probe field on numerical grids as functions of space and time. The results show that the continuous-wave input weak probe field can be switched on and off when the relative phase of the applied field is externally varied periodically in time. The proposed scheme may have applications in the design of optical switching and optical gain devices.