scholarly journals Mid-infrared transmission properties of amorphous germanium optical fibers

2010 ◽  
Vol 97 (7) ◽  
pp. 071117 ◽  
Author(s):  
Priyanth Mehta ◽  
Mahesh Krishnamurthi ◽  
Noel Healy ◽  
Neil F. Baril ◽  
Justin R. Sparks ◽  
...  
MRS Bulletin ◽  
2002 ◽  
Vol 27 (5) ◽  
pp. 370-380 ◽  
Author(s):  
B. Degamber ◽  
G. F. Fernando

AbstractThis article presents a review of optical-fiber-based process-monitoring techniques that can be used to track the chemical reactions that take place during the processing of materials, with specific reference to thermosetting resins. The techniques covered include quantitative process-monitoring methods based on near and mid-infrared, Raman, UV–visible, evanescent wave, and fluorescence spectroscopy. The basis for refractive-index-based process monitoring using optical fibers is also presented. The techniques described here can be readily applied to other classes of materials and other areas of interest such as aging and degradation. Recent advances in noncontact process monitoring are also presented.


2000 ◽  
Vol 54 (3) ◽  
pp. 450-455 ◽  
Author(s):  
Stephen R. Lowry ◽  
Jim Hyatt ◽  
William J. McCarthy

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.


1993 ◽  
Vol 8 (4) ◽  
pp. 885-889 ◽  
Author(s):  
Y. Messaddeq ◽  
A. Delben ◽  
M.A. Aegerter ◽  
A. Soufiane ◽  
M. Poulain

The limits of glass formation of new fluoroindate glass compositions have been determined for the basic systems InF3–BaF2–GdF3−20ZnF2−20SrF2–2XFn where × = Na, La and InF3–BaF2−20ZnF2−20SrF2−2GdF3–XFn, where × = Ca and Y. The incorporation of small amounts of GaF3 and/or GdF3 increases strongly the thermal glass stability. All the fluoroindate compositions studied are highly transparent in the mid-infrared range; their transmission edge is shifted beyond 7 μm and the theoretical attenuation coefficient, extrapolated at the CO laser wavelength emission, is typically α = 100 dB/km. Large bulks and preforms have been prepared allowing the drawing of optical fibers.


2018 ◽  
Vol 8 (9) ◽  
pp. 1637 ◽  
Author(s):  
Yiming Wu ◽  
Marcello Meneghetti ◽  
Johann Troles ◽  
Jean-Luc Adam

The mid-infrared spectral region is of great technical and scientific importance in a variety of research fields and applications. Among these studies, mid-infrared supercontinuum generation has attracted strong interest in the last decade, because of unique properties such as broad wavelength coverage and high coherence, among others. In this paper, the intrinsic optical properties of different types of glasses and fibers are presented. It turns out that microstructured chalcogenide fibers are ideal choices for the generation of mid-infrared supercontinua. The fabrication procedures of chalcogenide microstructured fibers are introduced, including purification methods of the glass, rod synthesis processes, and preform realization techniques. In addition, supercontinua generated in chalcogenide microstructured fibers employing diverse pump sources and configurations are enumerated. Finally, the potential of supercontinua for applications in mid-infrared imaging and spectroscopy is shown.


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