【摘要】 本文研究红外激光外差气体分析仪信号提取的数学模型,论证了外差气体分析仪的探测灵敏度可达10^-4ppb,这比直接探测方式约高九个量级.文中着重分析了方波控制激光器的频谱形式、光信号外差探测装置和电信号解调原理.最终导出外差气体分析仪气体浓度信息流程,据此绘制了方波控制CO₂激光外差气体分析仪原理方框图.更多还原

【Abstract】 Mathematical model of infrared laser heterodyne gas analyser for extracting signal is described in this paper. It is proved that the detecting sensitivity of heterodyne gas analyser can reach up to 10-4ppb, about nine orders of magnitute higher than that of direct detection. The spectrum form of square-wave controlled laser, optical signal heterodyne detecting device and principle of electrical signal demodulation are considered with emphasis. The flow chart of the gas density signal is deduced, according to which the block diagram of controlled CO2 laser heterodyne gas analyser is drawed.更多还原