Experimental setup used to detect high-contrast CPT resonances in Cs-vapor cells with PPOP. A Mach-Zehnder electro-optic modulator (MZ EOM) is used to generate optical sidebands with linear and parallel polarizations, frequency separated by the clock transition (9.192 GHz). A microwave-based stabilization technique of the transfer function operating point is implemented to stabilize the optical carrier rejection. TheMichelson interferometer is used to obtain at the output of the cube C1 two time-delayed optical components with orthogonal linear polarizations. The last quarter-wave plate before the cell creates alternating right and left circular polarizations for push-pull interaction. The photodiode PD detects the transmitted optical power through the vapor cell. MS, microwave synthesizer; PD, photodiode; EOM, electro-optic modulator; FPD, fast photodiode; , gas; QWP, quarter-wave plate; HWP, half-wave plate; BPF, bandpass filter; M1 and M2, mirrors; LNA, low-noise amplifier; SA, microwave spectrum analyzer; FP, Fabry-Perot interferometer.Reuse & Permissions