Near-resonant twin-beam generation from degenerate four-wave mixing in hot 133Cs vapor enabled by field-dressed energy levels.

Abstract

Squeezed light near an atomic resonance is beneficial for efficient atom-light quantum interfaces. It is desirable but challenging to directly generate in atoms due to excess noise from spontaneous emission and reabsorption. Here, we report on the use of energy-level modulation to actively control atomic coherence and interference in degenerate four-wave mixing (DFWM) and then to enhance the DFWM gain process for the generation of near-resonant squeezed twin beams. With this technique, we obtain a -2.6 dB intensity-difference squeezing detuned 100 MHz from the D1 F = 4 to F' = 4 transition of 133Cs.