A.J. McGettrick

TL;DR: In this article, an alternative approach to tunable diode-laser spectroscopy with wavelength modulation is described, which offers the simplicity of signal analysis of direct detection while providing all the advantages of phase-sensitive electronic detection.

TL;DR: In this article, a phasor decomposition method for analyzing signals in tunable diode laser spectroscopy with wavelength modulation is described, which enables recovery of the isolated and normalized residual amplitude modulation (RAM) signal from measured first harmonic signals at any chosen fundamental modulation frequency.

TL;DR: In this article, the residual amplitude modulation (RAM) technique and the phasor decomposition (PD) method were used for tunable diode laser spectroscopy (TDLS) measurements.

TL;DR: In this article, two new approaches to tunable diode laser spectroscopy (TDLS) in the near-IR, namely the residual amplitude modulation approach and the phasor decomposition method, are investigated for application in industrial process monitoring where the operating temperatures and pressures are high and subject to significant change.

TL;DR: In this article, an alternative approach to signal recovery in tunable diode laser spectroscopy with wavelength modulation is proposed and investigated, and absolute measurements of rotation / vibration gasline transmission functions, gas concentration and gas pressure can be made accurately without the need for calibration.