半导体抽运碱金属蒸气激光器（DPAL）具有量子效率高、气体介质循环流动散热、全电操作、结构紧凑等特点，是极具发展潜力的新型高能激光光源。其中，增益介质内碱金属原子浓度测量是对DPAL进行诊断测试的重要研究内容。通过利用单频分布布拉格反射(DBR)激光器波长扫描测量铷蒸气的吸收光谱，采用对激光器进行温度调节与电流扫描相结合的方法进行扫描光谱范围拼接，利用无跳模调谐范围为23 GHz的激光器实现了100 GHz的无跳模光谱扫描范围，在此基础上测量了充入大气压量级缓冲气体铷蒸气的完整吸收光谱。通过与理论计算结果进行参数拟合得到了铷原子浓度。该方法可应用于高功率抽运条件下流动介质DPAL中碱金属原子浓度的测量。

Diode-pumped alkali vapor laser (DPAL) has great potential in high power scaling due to its high quantum efficiencies, convenient thermal management by flowing the gaseous medium, all-electric operation, light weight and compact configuration, etc. The measurement of alkali concentration inside the gain medium is necessary and important to analyze the laser performance. By scanning the wavelength of the single-frequency distributed Bragg reflector (DBR) laser, the absorption spectrum of rubidium vapor is measured. By using the spectral matching method which is realized by integrated adjustment of the DBR′s driven current and operation temperature, the mode-hop free tuning range of DBR laser is extended from 23 GHz to 100 GHz. And the full absorption spectrum of rubidium D1 line is well scanned with buffer gas at an atmospheric pressure. By compared with the theoretical result, the concentration of alkali atom is obtained. This method can be applied for the measurement of alkali concentration under conditions of high power pumping with a flowing medium.