scholarly journals Frequency-comb-referenced molecular spectroscopy in the mid-infrared region

2011 ◽  
Vol 36 (21) ◽  
pp. 4122 ◽  
Author(s):  
Markku Vainio ◽  
Mikko Merimaa ◽  
Lauri Halonen
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
A. V. Muraviev ◽  
D. Konnov ◽  
K. L. Vodopyanov

Abstract Traditionally, there has been a trade-off in spectroscopic measurements between high resolution, broadband coverage, and acquisition time. Originally envisioned for precision spectroscopy of the hydrogen atom in the ultraviolet, optical frequency combs are now commonly used for probing molecular ro-vibrational transitions throughout broad spectral bands in the mid-infrared providing superior resolution, speed, and the capability of referencing to the primary frequency standards. Here we demonstrate the acquisition of 2.5 million spectral data points over the continuous wavelength range of 3.17–5.13 µm (frequency span 1200 cm−1, sampling point spacing 13–21 MHz), via interleaving comb-tooth-resolved spectra acquired with a highly-coherent broadband dual-frequency-comb system based on optical subharmonic generation. With the original comb-line spacing of 115 MHz, overlaying eight spectra with gradually shifted comb lines we fully resolve the amplitude and phase spectra of molecules with narrow Doppler lines, such as carbon disulfide (CS2) and its three isotopologues.


2014 ◽  
Vol 39 (17) ◽  
pp. 5050 ◽  
Author(s):  
I. Galli ◽  
S. Bartalini ◽  
P. Cancio ◽  
F. Cappelli ◽  
G. Giusfredi ◽  
...  

1997 ◽  
Vol 51 (5) ◽  
pp. 631-635 ◽  
Author(s):  
G. Budínová ◽  
J. Salva ◽  
K. Volka

The feasibility of applying molecular spectroscopy in the mid-infrared region to the quantitation of glucose and cholesterol in whole blood and in blood serum was examined by measuring the samples in the dry state on a polyethylene carrier. The partial least-squares (PLS) algorithm was employed to set up the calibration models. Analysis was performed by normalizing the spectra to a standard area. Evidence that this approach is warranted was obtained through experiments where potassium thiocyanate served as the internal standard. The following average PRESS1/2 values (PRESS stands for prediction residual error sum of squares) emerged from the calibration: glucose, 22.3 mg/dL; cholesterol, 31.3 mg/dL. Such errors are comparable with those achieved in attenuated total reflectance (ATR) measurements. The calibration models set up for blood serum samples fit better than those for whole blood samples. If the procedure of sample application onto the carrier is improved, the method may work well for the determination of glucose and cholesterol in whole blood and in blood serum.


1993 ◽  
Vol 1 (2) ◽  
pp. 99-108 ◽  
Author(s):  
P. Robert ◽  
M.F. Devaux ◽  
A. Qannari ◽  
M. Safar

Multivariate data treatments were applied to mid and near infrared spectra of glucose, fructose and sucrose solutions in order to specify near infrared frequencies that characterise each carbohydrate. As a first step, the mid and near infrared regions were separately studied by performing Principal Component Analyses. While glucose, fructose and sucrose could be clearly identified on the similarity maps derived from the mid infrared spectra, only the total sugar content of the solutions was observed when using the near infrared region. Characteristic wavelengths of the total sugar content were found at 2118, 2270 and 2324 nm. In a second step, the mid and near infrared regions were jointly studied by a Canonical Correlation Analysis. As the assignments of frequencies are generally well known in the mid infrared region, it should be useful to study the relationships between the two infrared regions. Thus, the canonical patterns obtained from the near infrared spectra revealed wavelengths that characterised each carbohydrate. The OH and CH combination bands were observed at: 2088 and 2332 nm for glucose, 2134 and 2252 nm for fructose, 2058 and 2278 nm for sucrose. Although a precise assignment of the near infrared bands to chemical groups within the molecules was not possible, the present work showed that near infrared spectra of carbohydrates presented specific features.


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