Intensity modulation effect on second harmonic profile of methane detection using wavelength modulation spectroscopy

摘要

The effect of intensity modulation (IM) of a tunable diode laser (TDL) on the wavelength modulation spectroscopy (WMS) and second harmonic (2f) lineshape profile of methane near 1666nm is experimentally investigated. The results are quantified and shown as a function of modulation depth.