TY - JOUR
T1 - Recovery of pure wavelength modulation second harmonic signal waveforms in distributed feedback diode laser-based photoacoustic spectroscopy
AU - Wang, Q.
AU - Chang, J.
AU - Wang, F. P.
AU - Wei, W.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - Application of second harmonic signal waveforms in distributed feedback diode laser (DFB DL)-based wavelength modulation (WM) spectroscopy is limited by the waveform distortions arising from modulation characteristics of DFB DL. The principle and implementation of a technique for the recovery of pure-WM second harmonic signal waveforms are proposed and particular attention is devoted to the problem in DFB DL-based photoacoustic spectroscopy (PAS). The disturbance factors responsible for the distorted second harmonic signal are analyzed, and their characteristics are utilized to eliminate the distortion. A simple and practical prototype for water vapor detection is assembled to demonstrate and validate this technique. The waveform of the recovered second harmonic signal in WM-PAS using the technique matches that of a calculated pure-WM second harmonic signal using a Fourier decomposition of the Lorentzian profile well with a high regression coefficient, R2= 0.9948. This offers the advantage of simplifying the spectral analysis, which, otherwise, would require a numerous calculation if the distortions were considered.
AB - Application of second harmonic signal waveforms in distributed feedback diode laser (DFB DL)-based wavelength modulation (WM) spectroscopy is limited by the waveform distortions arising from modulation characteristics of DFB DL. The principle and implementation of a technique for the recovery of pure-WM second harmonic signal waveforms are proposed and particular attention is devoted to the problem in DFB DL-based photoacoustic spectroscopy (PAS). The disturbance factors responsible for the distorted second harmonic signal are analyzed, and their characteristics are utilized to eliminate the distortion. A simple and practical prototype for water vapor detection is assembled to demonstrate and validate this technique. The waveform of the recovered second harmonic signal in WM-PAS using the technique matches that of a calculated pure-WM second harmonic signal using a Fourier decomposition of the Lorentzian profile well with a high regression coefficient, R2= 0.9948. This offers the advantage of simplifying the spectral analysis, which, otherwise, would require a numerous calculation if the distortions were considered.
U2 - 10.1016/j.sna.2016.04.042
DO - 10.1016/j.sna.2016.04.042
M3 - Article
SN - 0924-4247
VL - 245
SP - 54
EP - 62
JO - Sensors and Actuators, A: Physical
JF - Sensors and Actuators, A: Physical
ER -