本文33Σ+1以为中间激发态, 通过扫描光缔合光的频率得到了33Σ+1的不同振动态光谱。研究发现利用短程光缔合制备的超冷基态85Rb133mCs分子产率在33Σ+1(v=3)处较其他振动态更大, 33Σ+1(v=3)转动常数较邻近的振动态有明显变化且与23Π0－(v=14)的能量接近, 这些特征显示了这两个振动态的共振耦合特性。优化光缔合光的功率和光电离光的能量后, 我们得到X1Σ+(v=0)最低振动态超冷85Rb133Cs分子的产率为1.5×104/s。在考虑了分子波函数的宇称和跃迁选择定则后, 我们发现33Σ+1(v=3,J=1)存在单步自发辐射制备超冷基态85Rb133Cs分子的通道, 采用该通道可实现原子-分子相干转移直接制备超冷基态分子。

In this paper, we choose 33Σ+1 as an intermediate state and obtain relevant vibrational spectra by scanning the frequency of PA laser. It is found that the production rate of ultracold 85Rb133Cs molecules in the lowest vibrational state, formed by short-range PA, is larger in 33Σ+1(v=3) than other vibrational states, the corresponding rotational constant in 33Σ+1(v=3) is abrupt and the energy is close to 23Π0－(v=14) state. All of these display the characteristic of resonant coupling between these two states. After the optimization of PA laser intensity and photoionization power, the production rate of 85Rb133Cs molecules in X1Σ+(v=0) is measured to be around 1.5×104/s. With the consideration of the parity of the molecular wave function and the selection rules,we find that 33Σ+1(v=3,J=1) intermediate state has the passway that can spontaneously decay to ground state of ultracold 85Rb133Cs molecules via single pass which is meaningful to explore on direct transfer from atom to molecule using stimulated Raman adiabatic passage.