K. Duffin

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 paper, the authors present the full theoretical basis and range of techniques for calibration-free line-shape recovery to allow simultaneous measurements of concentration and pressure/temperature for a wide range of potential applications.

TL;DR: In this paper, the authors reported a more universal approach to the analysis of recovered residual AM signals and absolute absorption line shapes and provided the basis for a comparison of signal strength between the RAM signals recovered by the phasor decomposition approach and conventional first and second harmonic TDLS-WM signals.

TL;DR: A new fiber-optic technique to eliminate residual amplitude modulation in tunable diode laser wavelength modulation spectroscopy is presented, and the absolute absorption profile is directly recovered with high accuracy using 1f detection.