Ultra-sensitive cavity ring-down spectroscopy in the mid-infrared spectral region

A major concern with the use of near-infrared (NIR) spectroscopy in many QA/QC laboratories is the need for a simple reliable method of verifying the wavelength accuracy of the instrument. This requirement is particularly important in near-infrared spectroscopy because of the heavy reliance on sophisticated statistical vector analysis techniques to extract the desired information from the spectra. These techniques require precise alignment of the data points between the vectors corresponding to the standard and sample spectra. The National Institute of Standards and Technology (NIST) offers a Standard Reference Material (SRM 1921) for the verification and calibration of mid-infrared spectrometers in the transmittance mode. This standard consists of a 38 μm-thick film of polystyrene plastic. While SRM 1921 works well as a mid-infrared standard, a thicker sample is required for use as a routine standard in the near-infrared spectral region. The general acceptance and proven reliability of polystyrene as a standard reference material make it a very good candidate for a cost-effective NIR standard that could be offered as an internal reference for every instrument. In this paper we discuss a number of the parameters in a Fourier transform (FT)-NIR instrument that can affect wavelength accuracy. We also report a number of experiments designed to determine the effects of resolution, sample position, and optics on the wavelength accuracy of the system. In almost all cases the spectral reproducibility was better than one wavenumber of the values extrapolated from the NIST reference material. This finding suggests that a thicker sample of polystyrene plastic that has been validated with the SRM 1921 standard would make a cost-effective reference material for verifying wavelength accuracy in a medium-resolution FT-NIR spectrometer.

Download Full-text

Novel frequency comb spectroscopies in the near and mid infrared spectral region

Journal of Physical Chemistry & Biophysics ◽

10.4172/2161-0398.s1.002 ◽

2013 ◽

Vol s1 (01) ◽

Cited By ~ 1

Author(s):

Hans Schuessler

Keyword(s):

Spectral Region ◽

Frequency Comb ◽

Mid Infrared ◽

Infrared Spectral Region ◽

Infrared Spectral

Download Full-text

Vertical external cavity surface emitting PbTe/CdTe quantum dot lasers for the mid-infrared spectral region

Optics Letters ◽

10.1364/ol.39.006577 ◽

2014 ◽

Vol 39 (23) ◽

pp. 6577 ◽

Cited By ~ 6

Author(s):

A. Khiar ◽

M. Eibelhuber ◽

V. Volobuev ◽

M. Witzan ◽

A. Hochreiner ◽

...

Keyword(s):

Quantum Dot ◽

Spectral Region ◽

External Cavity ◽

Cavity Surface ◽

Quantum Dot Lasers ◽

Mid Infrared ◽

Infrared Spectral Region ◽

Infrared Spectral ◽

Cdte Quantum Dot

Download Full-text

Detection of Formaldehyde in Flames Using UV and MIR Absorption Spectroscopy

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2014-0563 ◽

2015 ◽

Vol 229 (4) ◽

Cited By ~ 2

Author(s):

Patrick Nau ◽

Julia Koppmann ◽

Alexander Lackner ◽

Andreas Brockhinke

Keyword(s):

Comparative Study ◽

Dimethyl Ether ◽

Absorption Spectroscopy ◽

Spectral Region ◽

Low Pressure ◽

Cavity Ring Down Spectroscopy ◽

Mid Infrared ◽

Highly Sensitive ◽

Absorption Technique ◽

Cavity Ring Down

AbstractAbsorption spectroscopy in the ultraviolet (UV) and mid-infrared (MIR) spectral region has been used in a comparative study for the detection of formaldehyde in laminar low pressure flames of dimethyl ether (DME) and methane. Both spectral regions were tested to explore respective advantages and limitations, especially for the detection of stable molecules in flames. In the UV, cavity ring-down spectroscopy (CRDS), a highly sensitive multi-pass absorption technique, has been used for the detection of formaldehyde in the

Download Full-text