Rb蒸汽中5S_(1/2)→5P_(3/2)激光激发的速度选择粒子数密度和饱和效应

The effect of saturation and velocity selective population in 5S_(1/2)-5P_(3/2) laser excitation in Rb vapor

利用一步激发的饱和吸收光谱技术测量了激发态Rb(5P3/2)态的原子密度,在激光线宽远小于Doppler线宽条件下。在激光功率40μW至5mW的范围内,测量了吸收系数,得到了5P3/2态的速度选择布居数密度。通过Rb空心阴极灯发出的5D→5P3/2窄谱线的吸收测量,也可以测得5P3/2态的原子密度,二种测量方法所得结果符合得很好。约2%基态原子被单模半导体激光器激发到5P3/2态。

Excited state population distribution created by 5S1/2→5P3/2 laser excitation in room temperature rubidium vapor was quantitatively analyzed applying absorption and saturation spectroscopy. When the laser linewidth was much smaller than the Doppler linewidth, the absorption coefficients were measured for a series of P780 powers between 40μW and 5mW, Population in the 5P3/2 level obtained from the saturation measurements was also determined by the absorption measurement of narrow spectral line from a Rb hollow cathode lamp. The agreement between the results obtained in these two ways is very good. It was shown that 2% of the gound state population could be transferred to the first excited state by pumping the Doppler broadened line with a single - mode narrow - band laser.