透過使用雙級聯四波混頻系統，我們成功在冷原子係綜中實現了將光子頻率從近紅外光波段（795 nm）轉換至通訊光波段（1367 nm）。我們還比較了在多重和單一賽曼態條件下的雙級聯四波混頻差異。目前，在多重和單一賽曼態下，我們分別觀察到最大的頻率轉換效率分別為20％和24％，這與理論預測有所偏差。此外，由於我們在實驗中所選用的單一賽曼態具有循環躍遷的特性，相對於多重賽曼態，我們能夠在單一賽曼態中觀察到轉頻光脈衝呈現出的慢光效應。

Using a double-cascade four-wave mixing system, we successfully achieved the conversion of photon frequency from the near-infrared wavelength range (795 nm) to the telecom wavelength range (1367 nm) within a cold atomic ensemble. We also compared the differences in double-cascade four-wave mixing under conditions of multiple and single Zeeman states. Currently, in both multiple and single Zeeman states, we have observed maximum frequency conversion efficiencies of 20% and 24%, respectively, which deviate slightly from theoretical predictions. Additionally, due to the cycling transition characteristic present in the single Zeeman state we employed in the experiment, relative to the multiple Zeeman state, we are able to observe the slow light effect of the converted light pulse within the single Zeeman state.

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