AI 中文总结
该研究利用超声速束和高分辨率cw可调谐二极管激光，测量Rb₂三种同位素异构体的958个振转跃迁，通过全局最小二乘分析得到B¹Π_u态更精确的Dunham系数等参数，拓展了前期相关研究。
AI 中文摘要
采用连续波（cw）可调谐二极管激光，在超声速分子束中对⁸⁵Rb₂、⁸⁵Rb⁸⁷Rb和⁸⁷Rb₂三种同位素异构体开展了高分辨率激光光谱研究。共记录了958个振转跃迁，覆盖至X¹Σ_g⁺(v''=0)→B¹Π_u(v'=1,2)和X¹Σ_g⁺(v''=1)→B¹Π_u(v'=1)振动带头部下方7 cm⁻¹处，光谱分辨率达3.3×10⁻⁴ cm⁻¹。尽管测量仅针对激发态B¹Π_u的v'=1和v'=2振动能级，但相较于Amiot和Vergès（《化学物理快报》274卷，91页，1997年）的前期工作，本研究凭借更高的分辨率及三种同位素异构体的密集低J'转动数据拓展了研究范围。结合新数据与已发表数据的全局最小二乘分析，得到了激发态B¹Π_u更精确的Dunham系数，显著优化了转动和振转耦合常数，此外还测定了三种同位素异构体B¹Π_u态的Λ双重分裂常数。
英文摘要
High-resolution laser spectroscopy of the $^{85}\mathrm{Rb}_2$, $^{85}\mathrm{Rb}^{87}\mathrm{Rb}$, and $^{87}\mathrm{Rb}_2$ isotopologues has been performed in a supersonic molecular beam using a continuous-wave (cw) tunable diode laser. A total of 958 rovibronic transitions were recorded up to $7~\mathrm{cm}^{-1}$ below the vibrational band heads of the $X^1Σ_g^+(v''=0)\rightarrow B^1Π_u(v'=1,2)$ and $X^1Σ_g^+(v''=1)\rightarrow B^1Π_u(v'=1)$ bands, with a spectral resolution of $3.3\times10^{-4}$~cm$^{-1}$. Although restricted to the $v'=1$ and $v'=2$ vibrational levels of the excited $B^1Π_u$ state, the measurements extend previous work by Amiot and Vergès [Chemical Physics Letters 274, 91 (1997)] through substantially higher resolution and dense low-$J'$ rotational data for all three isotopologues. A global least-squares analysis combining the new and published data, yields improved Dunham coefficients for the excited $B^1Π_u$ state, significantly refines rotational and rovibrational coupling constants. In addition, the $Λ$-doubling constants of $B^1Π_u$ state were determined for the three isotopologues.
