Autler–Townes spectroscopy of high-lying state by phase conjugate six-wave mixing

Abstract

An Autler-Townes (AT) spectroscopy based on phase conjugate six-wave mixing (SWM) is proposed to detect AT doublet of high-lying state in a Doppler-broadened cascade four-level system. It is found that the SWM spectrum is dependent strongly on the ratios between the magnitudes of the wave vectors. We discuss how the Doppler broadening affects the SWM spectrum from a time-domain viewpoint and find that, due the atomic motion, the atomic polarizations acquire different phases for atoms with different velocities as time evolves. The Doppler free SWM spectrum can be obtained only when the atomic polarization can be rephasing again at certain time after the interactions of all the incident fields.

A low noise, high fidelity cross phase modulation in multi-level atomic medium*

“…[11] However, in atomic gases, nonlinear effects can be enhanced by choosing different energy levels and transition pathways. Based on these features, strong nonlinear effects can be achieved by using electromagnetic induction transparency (EIT) [12][13][14][15][16][17] or weakly driven active Raman gain (ARG) [18][19][20][21][22][23][24][25][26][27][28] technologies. In particular, Artoni et al proposed a novel phaseby-phase control mechanism to achieve broadly tunable light phase shifts.…”