scholarly journals Fiber-Coupled Quartz-Enhanced Photoacoustic Spectroscopy System for Methane and Ethane Monitoring in the Near-Infrared Spectral Range

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5607
Author(s):  
Giansergio Menduni ◽  
Fabrizio Sgobba ◽  
Stefano Dello Russo ◽  
Ada Cristina Ranieri ◽  
Angelo Sampaolo ◽  
...  
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Near Infrared ◽  
Integration Time ◽  
Vapor Concentration ◽  
Acoustic Detection ◽  
Near Ir ◽  
Qepas Signal ◽  
Infrared Spectral ◽  
Lock In ◽  
Minimum Detection Limits

We report on a fiber-coupled, quartz-enhanced photoacoustic spectroscopy (QEPAS) near-IR sensor for sequential detection of methane (CH4 or C1) and ethane (C2H6 or C2) in air. With the aim of developing a lightweight, compact, low-power-consumption sensor suitable for unmanned aerial vehicles (UAVs)-empowered environmental monitoring, an all-fiber configuration was designed and realized. Two laser diodes emitting at 1653.7 nm and 1684 nm for CH4 and C2H6 detection, respectively, were fiber-combined and fiber-coupled to the collimator port of the acoustic detection module. No cross talk between methane and ethane QEPAS signal was observed, and the related peak signals were well resolved. The QEPAS sensor was calibrated using gas samples generated from certified concentrations of 1% CH4 in N2 and 1% C2H6 in N2. At a lock-in integration time of 100 ms, minimum detection limits of 0.76 ppm and 34 ppm for methane and ethane were achieved, respectively. The relaxation rate of CH4 in standard air has been investigated considering the effects of H2O, N2 and O2 molecules. No influence on the CH4 QEPAS signal is expected when the water vapor concentration level present in air varies in the range 0.6–3%.

scholarly journals Quartz-Enhanced Photoacoustic Detection of Ethane in the Near-IR Exploiting a Highly Performant Spectrophone

2020 ◽  
Vol 10 (7) ◽  
pp. 2447 ◽  
Author(s):  
Fabrizio Sgobba ◽  
Giansergio Menduni ◽  
Stefano Dello Russo ◽  
Angelo Sampaolo ◽  
Pietro Patimisco ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Gas Sensing ◽  
Signal To Noise Ratio ◽  
Quartz Tuning Fork ◽  
Integration Time ◽  
Exciting Light ◽  
Acoustic Detection ◽  
Photoacoustic Detection ◽  
Near Ir ◽  
Lock In

In this paper the performances of two spectrophones for quartz-enhanced photoacoustic spectroscopy (QEPAS)-based ethane gas sensing were tested and compared. Each spectrophone contains a quartz tuning fork (QTF) acoustically coupled with a pair of micro-resonator tubes and having a fundamental mode resonance frequency of 32.7 kHz (standard QTF) and 12.4 kHz (custom QTF), respectively. The spectrophones were implemented into a QEPAS acoustic detection module (ADM) together with a preamplifier having a gain bandwidth optimized for the respective QTF resonance frequency. Each ADM was tested for ethane QEPAS sensing, employing a custom pigtailed laser diode emitting at ~1684 nm as the exciting light source. By flowing 1% ethane at atmospheric pressure, a signal-to-noise ratio of 453.2 was measured by implementing the 12.4 kHz QTF-based ADM, ~3.3 times greater than the value obtained using a standard QTF. The minimum ethane concentration detectable using a 100 ms lock-in integration time achieving the 12.4 kHz custom QTF was 22 ppm.

scholarly journals Environmental Monitoring of Methane with Quartz-Enhanced Photoacoustic Spectroscopy Exploiting an Electronic Hygrometer to Compensate the H2O Influence on the Sensor Signal

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2935 ◽  
Author(s):  
Arianna Elefante ◽  
Giansergio Menduni ◽  
Hubert Rossmadl ◽  
Verena Mackowiak ◽  
Marilena Giglio ◽  
...  
Keyword(s):  
Water Vapor ◽  
Environmental Monitoring ◽  
Photoacoustic Spectroscopy ◽  
Simultaneous Detection ◽  
Vapor Concentration ◽  
Interband Cascade Laser ◽  
Qepas Signal ◽  
Monitoring Applications ◽  
Ch4 Concentration ◽  
Qepas Sensor

A dual-gas sensor based on the combination of a quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor and an electronic hygrometer was realized for the simultaneous detection of methane (CH4) and water vapor (H2O) in air. The QEPAS sensor employed an interband cascade laser operating at 3.34 μm capable of targeting a CH4 absorption line at 2988.8 cm−1 and a water line at 2988.6 cm−1. Water vapor was measured with both the electronic hygrometer and the QEPAS sensor for comparison. The measurement accuracy provided by the hygrometer enabled the adjustment of methane QEPAS signal with respect to the water vapor concentration to retrieve the actual CH4 concentration. The sensor was tested by performing prolonged measurements of CH4 and H2O over 60 h to demonstrate the effectiveness of this approach for environmental monitoring applications.

Trace gas detection based on photoacoustic spectroscopy in 3-D printed gas cell

2020 ◽  
Vol 28 (4) ◽  
pp. 236-242
Author(s):  
Shenlong Zha ◽  
Hongliang Ma ◽  
Changli Zha ◽  
Xueyuan Cai ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Near Infrared ◽  
Acoustic Pressure ◽  
Resonant Cavity ◽  
Photoacoustic Signal ◽  
Trace Gas ◽  
Integration Time ◽  
Photoacoustic Cell ◽  
Normal Atmospheric Pressure ◽  
Micro Resonator

A novel photoacoustic spectroscopy gas sensor based on a micro-resonator has been developed. The photoacoustic cell was designed and fabricated using 3-D printing and the photoacoustic cell volume was compressed significantly. This design greatly reduces the time of manufacturing the micro-resonator and the weight was lighter compared to traditional cells. Furthermore, the acoustic pressure distribution in the 3-D printed photoacoustic cell was analyzed by COMSOL Multiphysics software, which indicated that the strongest acoustic pressure occurred in the middle of the resonant cavity. The performance of the sensor was evaluated by detection of CH4 at normal atmospheric pressure used a near infrared distributed feedback laser emitted at 1653 nm. The characteristic of the photoacoustic signal under different pressures was also investigated. An Allan variance shows that the 3-D printed photoacoustic spectroscopy sensor has the detection limit of 1.44 ppmv (3σ) for CH4 detection at about 200 s integration time.

Mid-infrared laser beam steering based on Fourier transform OPO

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Jérôme Bourderionnet ◽  
Arnaud Brignon ◽  
Daniel Dolfi ◽  
Jean-Pierre Huignard
Keyword(s):  
Fourier Transform ◽  
Frequency Conversion ◽  
Near Infrared ◽  
Beam Steering ◽  
Optical Scanners ◽  
Near Ir ◽  
Infrared Laser Beam ◽  
Infrared Spectral Range ◽  
Optical Parametric ◽  
Infrared Spectral

Abstract:Inertia-less optical scanners are an essential building block for many systems, including remote sensing, spectroscopy, and optronics. Although many solutions provide efficient scanning devices in the visible to near-infrared spectral range today, none of these devices offers good performances in longer wavelengths like in the mid-IR range. The new rationale that is described in this paper is to take advantage of existing and well-proven steering techniques in the near IR and to reach mid-IR by frequency conversion in a specifically designed Fourier transform optical parametric oscillator.

Chemical Mapping in the Mid- and Near-IR Spectral Regions by Hadamard Transform/FT-IR Spectrometry

1997 ◽  
Vol 51 (4) ◽  
pp. 477-486 ◽  
Author(s):  
M. K. Bellamy ◽  
A. N. Mortensen ◽  
R. M. Hammaker ◽  
W. G. Fateley
Keyword(s):  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Hadamard Transform ◽  
Chemical Mapping ◽  
Ir Spectrometry ◽  
Near Ir ◽  
Heterogeneous Samples ◽  
Infrared Spectral ◽  
Ft Ir ◽  
Data Acquisition And Processing

A movable two-dimensional (2D) Hadamard encoding mask is obtained and combined with conventional FT-IR spectrometers for use in both the mid- and near-infrared spectral regions. Chemical maps and spectra of individual pixels of the maps can be obtained from heterogeneous samples by using this combination of a move-able 2D Hadamard encoding mask and an FT-IR spectrometer. We call the procedure Hadamard transform/FT-IR spectrometry. Spectra of usable signal-to-noise ratio and reliable chemical maps are obtained in reasonable data acquisition and processing time.

Size Effect on Optical Properties of Silicon Dioxide Hollow Particles

2020 ◽  
Vol 312 ◽  
pp. 26-31
Author(s):  
Viktoriia Iurina ◽  
Vitaly V. Neshchimenko ◽  
Chun Dong Li
Keyword(s):  
Optical Properties ◽  
Silicon Dioxide ◽  
Near Infrared ◽  
Photoelectron Spectra ◽  
Hollow Particles ◽  
X Ray ◽  
Near Ir ◽  
Infrared Spectral ◽  
Uv Visible ◽  
Spectral Ranges

The optical properties of silicon dioxide hollow particles with different size were investigated in UV/visible/near-IR region, as well as X-ray photoelectron spectra were analyzed. Synthesis of SiO2 hollow particles was carried out using a template method. It was established that hollow particle reflectance lower than bulk microparticles. Absorptance in the red and near infrared spectral ranges increases with decreasing size of hollow particles, but in the UV-region conversely. This is due to different absorption centers.

Plasmon-assisted interaction of Si with light, for cancer hyperthermia and electromagnetic energy harvest

2020 ◽  
Vol 92 (2) ◽  
pp. 20101
Author(s):  
Behnam Kheyraddini Mousavi ◽  
Morteza Rezaei Talarposhti ◽  
Farshid Karbassian ◽  
Arash Kheyraddini Mousavi
Keyword(s):  
Silicon Nanowires ◽  
Metallic Nanoparticles ◽  
Near Infrared ◽  
Optical Transition ◽  
Electromagnetic Energy ◽  
Energy Harvest ◽  
Absorption Enhancement ◽  
Ir Absorption ◽  
Absorption Mechanism ◽  
Near Ir

Metal-assisted chemical etching (MACE) is applied for fabrication of silicon nanowires (SiNWs). We have shown the effect of amorphous sheath of SiNWs by treating the nanowires with SF6 and the resulting reduction of absorption bandwidth, i.e. making SiNWs semi-transparent in near-infrared (IR). For the first time, by treating the fabricated SiNWs with copper containing HF∕H2O2∕H2O solution, we have generated crystalline nanowires with broader light absorption spectrum, up to λ = 1 μm. Both the absorption and photo-luminescence (PL) of the SiNWs are observed from visible to IR wavelengths. It is found that the SiNWs have PL at visible and near Infrared wavelengths, which may infer presence of mechanisms such as forbidden gap transitions other can involvement of plasmonic resonances. Non-radiative recombination of excitons is one of the reasons behind absorption of SiNWs. Also, on the dielectric metal interface, the absorption mechanism can be due to plasmonic dissipation or plasmon-assisted generation of excitons in the indirect band-gap material. Comparison between nanowires with and without metallic nanoparticles has revealed the effect of nanoparticles on absorption enhancement. The broader near IR absorption, paves the way for applications like hyperthermia of cancer while the optical transition in near IR also facilitates harvesting electromagnetic energy at a broad spectrum from visible to IR.

Metastructures for the Giant Enhancement of Raman Scattering in the Near Infrared Spectral Range

JETP Letters ◽  
2020 ◽  
Vol 112 (1) ◽  
pp. 31-36
Author(s):  
V. I. Kukushkin ◽  
V. E. Kirpichev ◽  
E. N. Morozova ◽  
V. V. Solov’ev ◽  
Ya. V. Fedotova ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral

scholarly journals ALD Deposited ZnO:Al Films on Mica for Flexible PDLC Devices

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1011
Author(s):  
Dimitre Z. Dimitrov ◽  
Zih Fan Chen ◽  
Vera Marinova ◽  
Dimitrina Petrova ◽  
Chih Yao Ho ◽  
...  
Keyword(s):  
Near Infrared ◽  
Atomic Layer ◽  
Optical Transmittance ◽  
Force Microscopy ◽  
Flexible Polymer ◽  
Layer Deposition ◽  
Polymer Dispersed ◽  
Muscovite Mica ◽  
Infrared Spectral ◽  
Continuous Bending

In this work, highly conductive Al-doped ZnO (AZO) films are deposited on transparent and flexible muscovite mica substrates by using the atomic layer deposition (ALD) technique. AZO-mica structures possess high optical transmittance at visible and near-infrared spectral range and retain low electric resistivity, even after continuous bending of up to 800 cycles. Structure performances after bending tests have been supported by atomic force microscopy (AFM) analysis. Based on performed optical and electrical characterizations AZO films on mica are implemented as transparent conductive electrodes in flexible polymer dispersed liquid crystal (PDLC) devices. The measured electro-optical characteristics and response time of the proposed devices reveal the higher potential of AZO-mica for future ITO-free flexible optoelectronic applications.

scholarly journals Phenotypic and genetic variation of ultraviolet–visible-infrared spectral wavelengths of bovine meat

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Giovanni Bittante ◽  
Simone Savoia ◽  
Alessio Cecchinato ◽  
Sara Pegolo ◽  
Andrea Albera
Keyword(s):  
Meat Quality ◽  
Genetic Improvement ◽  
Near Infrared ◽  
Infrared Region ◽  
Phenotypic Variance ◽  
Quality Traits ◽  
Meat Quality Traits ◽  
Infrared Spectral ◽  
Portable Spectrometers ◽  
Absorbance Spectra

AbstractSpectroscopic predictions can be used for the genetic improvement of meat quality traits in cattle. No information is however available on the genetics of meat absorbance spectra. This research investigated the phenotypic variation and the heritability of meat absorbance spectra at individual wavelengths in the ultraviolet–visible and near-infrared region (UV–Vis-NIR) obtained with portable spectrometers. Five spectra per instrument were taken on the ribeye surface of 1185 Piemontese young bulls from 93 farms (13,182 Herd-Book pedigree relatives). Linear animal model analyses of 1481 single-wavelengths from UV–Vis-NIRS and 125 from Micro-NIRS were carried out separately. In the overlapping regions, the proportions of phenotypic variance explained by batch/date of slaughter (14 ± 6% and 17 ± 7%,), rearing farm (6 ± 2% and 5 ± 3%), and the residual variances (72 ± 10% and 72 ± 5%) were similar for the UV–Vis-NIRS and Micro-NIRS, but additive genetics (7 ± 2% and 4 ± 2%) and heritability (8.3 ± 2.3% vs 5.1 ± 0.6%) were greater with the Micro-NIRS. Heritability was much greater for the visible fraction (25.2 ± 11.4%), especially the violet, blue and green colors, than for the NIR fraction (5.0 ± 8.0%). These results allow a better understanding of the possibility of using the absorbance of visible and infrared wavelengths correlated with meat quality traits for the genetic improvement in beef cattle.

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