Fig. 1: Schematic diagram.
From: Temporal analog of Fabry-Pérot resonator via coherent population trapping
a Energy levels of 87Rb D1 line transitions under the lin∣∣lin configuration. The black and red lines, respectively, denote two independent six-level and five-level subsystems. \({\Omega }_{1,\pm 1}^{a}\) and \({\Omega }_{2,\pm 1}^{b}\) are the Rabi frequencies of five-level subsystems, Γ is the decay rate from excited states to ground states, and ωhfs is the zero-field hyperfine splitting of the ground state. \(\left|1\right\rangle\), \(\left|2\right\rangle\), \(\left|3\right\rangle\), and \(\left|4\right\rangle\) are four ground states of five-level subsystems. b The temporal analog of FPR, σ denotes the form of spin coherence, Nc is the total number of CPT pulses. The l-th CPT pulse, which corresponds to the (Nc − l + 1)-th reflection event with the reflection coefficient \({{{\mathcal{R}}}}(l)\) and the transmission coefficient \({{{\mathcal{T}}}}(l)\), transmits \({\sigma }_{{N}_{{{{\rm{c}}}}}-l+1}\), which is part of σ.
