Innovative Substrate-Integrated Hollow Waveguide Coupled Attenuated Total Reflection Sensors for Quantum Cascade Laser Based Infrared Spectroscopy in Harsh Environments

2021 ◽  
pp. 000370282110643
Author(s):  
Andrea Teuber ◽  
Robert Stach ◽  
Julian Haas ◽  
Boris Mizaikoff
Keyword(s):  
Quantum Cascade Lasers ◽  
Evanescent Field ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Ir Radiation ◽  
Metal Structures ◽  
Quantum Cascade ◽  
Hollow Waveguides ◽  
Optical Alignment ◽  
Atr Spectroscopy

An innovative mid-infrared spectroscopic sensor system based on quantum cascade lasers has been developed. The system combines the versatility of substrate-integrated hollow waveguides (IHWGs) with the robustness of attenuated total reflection (ATR) crystals employed as internal reflection waveguides for evanescent field sensing. IHWGs are highly reflective metal structures that propagate infrared (IR) radiation and were used as light pipes for coupling radiation into the ATR waveguide. The combined IHWG-ATR device has been designed such that the utmost stability and robustness of the optical alignment were ensured. This novel assembly enables evanescent field absorption measurements at yet unprecedently harsh conditions, that is, high pressure and temperature. Combining these advantages, this innovative sensor assembly is perfectly suited for taking ATR spectroscopy into the field where the robustness of the assembly and optical alignment is essential.

scholarly journals Sensing chlorinated hydrocarbons via miniaturized GaAs/AlGaAs thin-film waveguide flow cells coupled to quantum cascade lasers

2016 ◽  
Vol 8 (36) ◽  
pp. 6602-6606 ◽  
Author(s):  
Julian Haas ◽  
Robert Stach ◽  
Markus Sieger ◽  
Zana Gashi ◽  
Matthias Godejohann ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Quantum Cascade Lasers ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Mid Infrared ◽  
Flow Cells ◽  
Quantum Cascade ◽  
Low Levels ◽  
Atr Spectroscopy ◽  
Cascade Lasers

Mid-infrared (MIR) sensors based on attenuated total reflection (ATR) spectroscopy provide robust, rapid and sensitive platforms for the detection of low levels of organic molecules and pollutants.

scholarly journals Infrared Spectroscopy with a Fiber-Coupled Quantum Cascade Laser for Attenuated Total Reflection Measurements Towards Biomedical Applications

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5130 ◽  
Author(s):  
Ine L. Jernelv ◽  
Karina Strøm ◽  
Dag Roar Hjelme ◽  
Astrid Aksnes
Keyword(s):  
Infrared Spectroscopy ◽  
Quantum Cascade Lasers ◽  
Spectral Power ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Mid Infrared ◽  
Quantum Cascade ◽  
In Vitro Investigation

The development of rapid and accurate biomedical laser spectroscopy systems in the mid-infrared has been enabled by the commercial availability of external-cavity quantum cascade lasers (EC-QCLs). EC-QCLs are a preferable alternative to benchtop instruments such as Fourier transform infrared spectrometers for sensor development as they are small and have high spectral power density. They also allow for the investigation of multiple analytes due to their broad tuneability and through the use of multivariate analysis. This article presents an in vitro investigation with two fiber-coupled measurement setups based on attenuated total reflection spectroscopy and direct transmission spectroscopy for sensing. A pulsed EC-QCL (1200–900 cm − 1 ) was used for measurements of glucose and albumin in aqueous solutions, with lactate and urea as interferents. This analyte composition was chosen as an example of a complex aqueous solution with relevance for biomedical sensors. Glucose concentrations were determined in both setup types with root-mean-square error of cross-validation (RMSECV) of less than 20 mg/dL using partial least-squares (PLS) regression. These results demonstrate accurate analyte measurements, and are promising for further development of fiber-coupled, miniaturised in vivo sensors based on mid-infrared spectroscopy.

Application Of Systems With Total Internal Reflection At Novosibirsk Free Electron Laser For Spectroscopy In The Terahertz Range

2016 ◽  
Vol 11 (3) ◽  
pp. 72-82
Author(s):  
Vasily Gerasimov ◽  
Elvira Grigorieva ◽  
Boris Knyazev ◽  
Yuliya Choporova
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Quantum Cascade Lasers ◽  
Attenuated Total Reflection ◽  
Terahertz Range ◽  
Optical Systems ◽  
Early Diagnosis Of Cancer ◽  
Infrared Spectral ◽  
Atr Spectroscopy ◽  
Spectral Ranges

Attenuated total reflection (ATR) spectroscopy is widely used in the visible and infrared spectral ranges. Progress in the development of laboratory scale monochromatic sources of terahertz radiation, such as quantum cascade lasers, suggests that in the near future this kind of spectrometers will be widely spread in the terahertz range. For this reason, the development of ATR based methods and devices is highly relevant. In this paper, we discuss the features of the use of ATR spectroscopy in the terahertz range, and describe some of the optical systems, designed for experiments at the Novosibirsk free electron laser (NovoFEL). We show that in the terahertz range the ATR spectroscopy has a number of significant advantages over the absorption spectroscopy. As an example, we are discussing the possibility of using terahertz polarimetry to develop a method for early diagnosis of cancer via the detection of left-handed to right-handed polysaccharide enantiomers ratio. Spectra of selected polysaccharides were recorded with a standard Fourier spectrometer using developed by us an ATR unit. The possibility of studying the polarization characteristics of polysaccharides in aqueous solutions using spectrally selective polarimeter with the NovoFEL as a tunable radiation source was demonstrated.

On the Nature of the Evanescent Wave

2013 ◽  
Vol 67 (2) ◽  
pp. 126-131 ◽  
Author(s):  
Milan Milosevic
Keyword(s):  
Theoretical Result ◽  
Experimental Method ◽  
Evanescent Wave ◽  
Research Topic ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Entire Field ◽  
Mental Picture ◽  
Basic Understanding ◽  
Atr Spectroscopy

This is an unusual paper in that it does not address a particular research topic or present a novel experimental method or a new theoretical result. This paper addresses our basic understanding of the nature of the evanescent wave, the wave that is the basis of the entire field of Attenuated Total Reflection (ATR) spectroscopy. I recently had the opportunity to reexamine the foundations of ATR spectroscopy and was surprised to have had to change my own mental picture of the evanescent wave that I have built over the last 25 years. Over the years I have had numerous discussions with a large number of workers in the field as well as with my former mentor, and one of the originators and the principal developer of ATR spectroscopy, the late N.J. Harrick. Everything brought up in all these discussions was perfectly consistent with my old mental picture of the evanescent wave. Thus, I believe that the picture of the evanescent wave that I had is virtually universally held by workers in the field. This paper describes the new picture of the evanescent wave that emerged from said reexamination process.

Infrared attenuated total reflection (IR-ATR) spectroscopy for detecting drugs in human saliva

2011 ◽  
Vol 4 (6) ◽  
pp. 420-429 ◽  
Author(s):  
Kerstin M.-C. Hans ◽  
Susanne Müller ◽  
Markus W. Sigrist
Keyword(s):  
Human Saliva ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Atr Spectroscopy
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