Parametric Simulation and Analysis of Oxygen Detection Based on Wavelength Modulation Spectroscopy

Modulation parameters are main factors of wavelength modulation spectroscopy (WMS) technique because they can influence both performance and accuracy of the detection system by changing absorption signal characteristics. Absorption spectroscopy parameters of oxygen near 760nm were obtained through the HIRTAN database, simulation model of oxygen detection system was designed with the second harmonic linear expressions, and process of wavelength modulation spectroscopy and second harmonic signal extraction were simulated. Simulation results show that the best center wavelength is 760.885 nm and the best wavelength offset is 20 pm, which can obtain by adjusting the laser's DC bias current and scanning current respectively, and the modulation index is chosen between 1 and 2.2. This simulation test is very helpful to giving pertinent parameters of the real oxygen detection system.