Radiative lifetime measurement of ultracold cesium Rydberg states by a simplified optical pumping method

We demonstrate one simplified all-optical method to measure the radiative lifetime of ultracold cesium (Cs) Rydberg atoms. This method is based on photodetection of one ground state atomic absorption in a ladder-type electromagnetic induced transparency (EIT), which contains one ground state, one intermediate state, and one Rydberg state. In the presence and absence of optical pumping between the Rydberg state and the intermediate state, the absorption difference with varying delay time can reconstruct the population evolution of target Rydberg atoms. By using this method, the radiative lifetimes of 50S_1/2 and 50D_5/2 of Cs atoms are measured to be 53(9)µs and 42(9)µs, respectively, which are consistent with theoretical calculations. The agreements show the reliability of our presented method, which can provide a route for researching light-matter interaction behavior without the need to quantify absorption characteristic.