半导体抽运碱金属蒸气激光器(DPAL)是具有潜力的新型高能激光光源，高功率抽运条件下，铷原子会发生电离，对激光器性能产生负面影响。铷原子主要电离通道之一是抽运光谱(中心波长780 nm)和远翼776 nm 成分引起的5S→5P→5D 的级联效应以及后续的光电离过程。为了定量测量铷DPAL 电离度，需要搭建窄线宽776 nm 高功率半导体光源以模拟780 nm 抽运光的远翼光谱成分。基于Littrow 结构实现了窄线宽776 nm 半导体激光输出，激光线宽小于0.15 nm，功率大于10 W，外腔效率为67%；利用该激光器进行了780 nm 和776 nm 级联抽运实验，观察到显著增强的荧光信号。

Diode-pumped alkali vapor laser (DPAL) is a candidate in high power laser field. Under conditions of high-power pumping, ionization process will occur in DPAL′s gain medium, which has a negative impact on laser performance. One of the main rubidium atomic ionization channel is cascaded effect (5S→5P→5D) induced by the 776 nm far wing spectral component of the 780 nm diode pump source. In order to quantitatively measure the degree of ionization of rubidium DPAL, frequency-narrowed 776 nm high power semiconductor light source is needed to simulate the far wing of 780 nm pump light. Based on Littrow configuration, a linenarrowed 776 nm semiconductor laser output is realized, with spectral linewidth of less than 0.15 nm, output power of more than 10 W, and external cavity efficiency of 67%. By using 780 nm and 776 nm cascade pumping, a significant enhancement of fluorescence signal has been observed.