Direct conversion of slow light into a stationary light pulse

Analysis on direct transforming the slow light into the stationary light pulse (SLP) is presented. Without the process of turning the slow light into the coherence between the lower levels, the generation of SLP is more efficient. The Maxwell-Liouville equations are employed to study the light pulse dynamics in the samples coherently driven by a bichromatic standing wave. The solution indicates that the forward and backward components of the SLP approach to each other exponentially. Such property is described by introducing a quantity called characteristic length, which appeared to be the ratio of the optical coherence decay rate and the coefficient of the driving term in Maxwell equation. The necessary length for completing the conversion can be estimated as five times the characteristic length. Several materials are analyzed here, including the ${}^{87}$Rb atoms with different densities, Pr${}^{3+}$-doped yttrium orthosilicate (Pr:YSO), and nitrogen-vacancy color centers in diamond (N-V centers). The values of the characteristic length for the corresponding materials are calculated, as well as the necessary length.