Laser Q-switching based on electromagnetically induced transparency

Laser Q-switching is a critical technique that enables periodic modulation of cavity loss and has been widely used to generate giant laser pulses. In this paper, an innovative active Q-switching laser model based on the mechanism of electromagnetically induced transparency (EIT) is proposed. The system utilizes a three-level atomic system that interacts with both the cavity mode and an external strong coupling field, acting as a dynamically tunable loss medium. By controlling the coupling field intensity, the cavity loss can be dynamically modulated due to the EIT effect, thereby achieving active Q-switching operation. Numerical simulations demonstrate that the threshold inversion population is reduced by more than one order of magnitude during EIT activation, which indicates the feasibility of this kind of Q-switching.