【摘要】 可调谐半导体激光吸收光谱（TDLAS）是近年发展起来的一种激光光谱气体检测技术，相比于常见的电化学、离子导电陶瓷等技术，其具有选择性强、灵敏度高、响应快、可在线测量、抗背景光谱干扰能力强等优点，适用于复杂环境中气体的长期在线检测。氧气（O₂）是人类生存环境中的重要气体，O₂浓度的检测在生产生活各个领域应用广泛、意义重大。基于此，本文采用TDLAS技术对空气中的O₂进行高灵敏度测量。采用输出波长为760 nm的半导体激光器作为光源，直接吸收光谱法获得环境中的氧气浓度为20.56%，最小检测极限为5.53×10^-3。在波长调制方法中，优化了激光波长调制深度，得到了完整的二次谐波波形，可用于标定氧气浓度。此系统的信噪比为380.74，最小检测极限约为540×10^-6。本文的传感系统具有良好的O₂检测能力，可广泛用于各个领域中的O₂浓度检测。更多还原

【Abstract】 Tunable Diode Laser Absorption Spectroscopy （TDLAS） is a recently developed laser spectral gas detection technology.Compared with common oxygen sensors such as electrochemical devices and ionic conductive ceramics,TDLAS has the advantages of high selectivity and sensitivity,fast response,on-line measurement and strong anti-background spectral interference ability.Oxygen （O₂） is an important gas in habitable environments and is greatly significant to industrial production and human life,and the detection of O₂ concentration is also widely used in these fields.Based on this,we adopt TDLAS technology to carry out high sensitivity measurements of O₂ in air.Using a semiconductor laser with an output wavelength of 760 nm as the light source,the oxygen concentration in the environment is 20.56% by direct absorption spectroscopy,and the minimum detection limit is 5.53×10^-3.In the wavelength modulation spectroscopy method,the laser wavelength modulation depth is optimized to obtain a complete second harmonic waveform,which can be used to calibrate the oxygen concentration.The SNR of the system is 380.74,and the minimum detection limit is about 540×10^-6.The system realized in this paper has good oxygen detection ability and can be widely used in various fields of oxygen concentration detection.更多还原