【摘要】 可调谐二极管激光吸收光谱技术(TDLAS)是利用二极管激光器的波长扫描和电流调谐特性来实现痕量气体吸收曲线二次谐波检测的一种新技术,具有高灵敏、高选择性、高精度等特点。理论分析和实验结果表明:利用二次谐波检测到的信号特征除了与被测气体的吸收特征有关外,还与波长扫描参数和电流调制参数有密切的关系。通过研究不同波长的扫描参数和在功率调制参数下的二次谐波曲线,分析了它们的波形特征和稳定性,以便寻求最佳的波长扫描参数和功率调制参数,从而使二次谐波曲线的稳定性和形状达到最佳。更多还原

【Abstract】 Tunable diode laser absorption spectroscopy (TDLAS) is a new trace gas detection technique provided with high sensitivity, high selectivity and high precision. It makes use of a tunable diode laser scanning in wavelength and tuning in current. Theory analysis and experiment results indicate that the second-harmonic signal characteristic relates to the absorption characteristic of measured gas and the parameter of wave scan and current modulation. The second-harmonic curve under different wave scan parameter and power modulation parameter is studied, their wave characteristic and stability are analyzed, in order to find out the optimize detection parameters of wave scan and power modulation, the best second-harmonic curve is gotten.更多还原