首次报道了钠分子一系列里德堡能级的无多普勒加宽光光三共振(DF-OOTR)激发荧光光谱,测量了其谱线宽度和其谱线位置随温度、外加气体压力的变化情况。结果表明,钠分子里德堡能级(n=5～8)的自然宽度(含均匀加宽)在60～130 MHz之间,其大小主要与主量子数n有关。随钠原子浓度增大(温度升高),或外加Ar气压力增大时,钢分子各个里德堡能级谱线均出现红移,数量在100 MHz/τ之内,但位移速率大小不一。

This paper reports for the first time the Doppler-free optical-optical tripleresonance(DF-OOTR) excitation fluorescence spectra for a series of Rydberg energy levels in sodium molecules, and the linewidths and lineshifts under the variations of temperature and foreign buffer-gas pressure. The results demonstrated that the natural widths(including homogeneuos broadening) of these Rydberg energy levels (n=5～8)are between 60～130 MHz, and mainly depend on the principal quantum number n. All these levels are in red line-shifts with the increase of atomic density (the increase of temperature) or foreign buffer-gas (Ar) pressure, but with different shift rate within 100 MHz/τ.