Observation of four-wave mixing in caesium atoms using a noncycling transition

In this paper the generation of four-wave mixing (FWM) signal using anoncycling transition of caesium atoms is investigated when the pumping laseris locked to the transition $6{rm S}_{1/2}F=4to6{rm P}_{3/2}F'=4$, andmeanwhile the probe frequency is scanned across the $6{rm S}_{1/2}F=4to6{rm P}_{3/2}$ transition. The efficiency of the four-wave mixing signalas a function of the intensity of the pumping beams and the detuning of thepumping beams is also studied. In order to increase the detectionefficiency, a repumping laser which is resonant with $6{rm S}_{1/2}F=3to 6{rm P}_{3/2}F'=4$ transition is used. A theoretical model is alsointroduced, and the theoretical results are in qualitative agreement withexperimental ones.