Related Experiment Video
Updated: Aug 20, 2026

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown
Published on: February 14, 2014
Diode laser spectroscopy of ammonia and ethylene overtones
1Istituto per i Processi Chimico-Fisici del CNR, Area della Ricerca, Via G. Moruzzi 1, I-56124 Pisa, Italy. lucchesini@ipcf.cnr.it
Abstract:
Some overtone absorption lines of ammonia and ethylene have been examined by using a tunable diode laser (TDL) spectrometer in the region around 12,650 and 11,800 cm(-1), respectively. The spectrometer sources are commercially available double heterostructure InGaAlAs and AlGaAs TDLs operating in the "free-running" mode. The high resolving power ( approximately 10(7) ) of the spectrometer permitted the detection and the study of the line positions of such molecules with a precision better than 0.01 cm(-1). In order to maximize the signal to noise ratio and to extract the necessary informations either on the line width and on the line position for the detected molecular resonances, the wavelength modulation spectroscopy (WMS) along with the second harmonic detection techniques have been applied. For this purpose, the fitting procedure took into account the instrumental effects and the amplitude modulation (AM) always associated with the frequency modulation (FM) of these type of sources. This technique permitted also the measurement of the collisional-broadening and -shifting coefficients by different buffer gases at room temperature.
Related Concept Videos
NMR Spectroscopy Of Amines
¹H NMR of Labile Protons: Deuterium (²H) Substitution
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
¹H NMR of Labile Protons: Temporal Resolution
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
UV–Vis Spectroscopy: Molecular Electronic Transitions

