A novel wavelet denoising (WD) assisted wavelength modulation technique is proposed for improving near-infrared detection performance on methane concentration based on tunable diode laser absorption spectroscopy (TDLAS). Due to the ability of multi-level
The intracavity photon density is assumed to be of Gaussian spatial distributions and its longitudinal variation is also considered in the rate equations for a laser diode (LD) end-pumped passively Q-switched Nd:YVO4 laser with GaAs saturable absorber. Th