The high-resolution absorption spectroscopy branch on the VUV beamline DESIRS at SOLEIL

2016 ◽  
Vol 23 (4) ◽  
pp. 887-900 ◽  
Author(s):  
Nelson de Oliveira ◽  
Denis Joyeux ◽  
Mourad Roudjane ◽  
Jean-François Gil ◽  
Bertrand Pilette ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Spectral Resolution ◽  
Tunable Laser ◽  
High Spectral Resolution ◽  
Spectral Window ◽  
Wide Range ◽  
Sample Chamber ◽  
Moderate Resolution ◽  
Gaseous Sample ◽  
Selection Of

A VUV absorption spectroscopy facility designed for ultra-high spectral resolution is in operation as a dedicated branch on the DESIRS beamline at Synchrotron SOLEIL. This branch includes a unique VUV Fourier transform spectrometer (FTS) and a dedicated versatile gas sample chamber. The FTS instrument can cover a large UV–VUV spectral range from 4 to 30 eV, with an ultimate line width of 0.08 cm−1on a large spectral window, ΔE/E= 7%, over which all spectral features can be acquired in a multiplex way. The performance can be considered to be a middle ground between broadband moderate-resolution spectrometers based on gratings and ultra-high-spectral-resolution VUV tunable-laser-based techniques over very narrow spectral windows. The various available gaseous-sample-handling setups, which function over a wide range of pressures and temperatures, and the acquisition methodology are described. A selection of experimental results illustrates the performance and limitations of the FTS-based facility.

scholarly journals A coma-free super-high resolution optical spectrometer using 44 high dispersion sub-gratings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hua-Tian Tu ◽  
An-Qing Jiang ◽  
Jian-Ke Chen ◽  
Wei-Jie Lu ◽  
Kai-Yan Zang ◽  
...  
Keyword(s):  
High Resolution ◽  
Spectral Resolution ◽  
Wavelength Region ◽  
Ultra Violet ◽  
High Spectral Resolution ◽  
Visible Range ◽  
High Dispersion ◽  
Charge Coupled Device ◽  
Wide Range ◽  
High Resolution Spectrometer

AbstractUnlike the single grating Czerny–Turner configuration spectrometers, a super-high spectral resolution optical spectrometer with zero coma aberration is first experimentally demonstrated by using a compound integrated diffraction grating module consisting of 44 high dispersion sub-gratings and a two-dimensional backside-illuminated charge-coupled device array photodetector. The demonstrated super-high resolution spectrometer gives 0.005 nm (5 pm) spectral resolution in ultra-violet range and 0.01 nm spectral resolution in the visible range, as well as a uniform efficiency of diffraction in a broad 200 nm to 1000 nm wavelength region. Our new zero-off-axis spectrometer configuration has the unique merit that enables it to be used for a wide range of spectral sensing and measurement applications.

scholarly journals Application of Near-Infrared Optical Feedback Cavity Enhanced Absorption Spectroscopy (OF-CEAS) to the Detection of Ammonia in Exhaled Human Breath

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3686
Author(s):  
Zhifu Luo ◽  
Zhongqi Tan ◽  
Xingwu Long
Keyword(s):  
Detection Limit ◽  
Absorption Spectroscopy ◽  
Spectral Resolution ◽  
Optical Feedback ◽  
Low Pressure ◽  
High Spectral Resolution ◽  
Trace Gas ◽  
Human Breath ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy

The qualitative and quantitative analysis to trace gas in exhaled human breath has become a promising technique in biomedical applications such as disease diagnosis and health status monitoring. This paper describes an application of a high spectral resolution optical feedback cavity enhanced absorption spectroscopy (OF-CEAS) for ammonia detection in exhaled human breath, and the main interference of gases such as CO2 and H2O are approximately eliminated at the same time. With appropriate optical feedback, a fibered distributed feedback (DFB) diode laser emitting at 1531.6 nm is locked to the resonance of a V-shaped cavity with a free spectral range (FSR) of 300 MHz and a finesse of 14,610. A minimum detectable absorption coefficient of αmin = 2.3 × 10−9 cm−1 is achieved in a single scan within 5 s, yielding a detection limit of 17 ppb for NH3 in breath gas at low pressure, and this stable system allows the detection limit down to 4.5 ppb when the spectra to be averaged over 16 laser scans. Different from typical CEAS with a static cavity, which is limited by the FSR in frequency space, the attainable spectral resolution of our experimental setup can be up to 0.002 cm−1 owing to the simultaneous laser frequency tuning and cavity dither. Hence, the absorption line profile is more accurate, which is most suitable for low-pressure trace gas detection. This work has great potential for accurate selectivity and high sensitivity applications in human breath analysis and atmosphere sciences.

scholarly journals Long-term validation of ESA operational retrieval (version 6.0) of MIPAS Envisat vertical profiles of methane, nitrous oxide, CFC11, and CFC12 using balloon-borne observations and trajectory matching

2016 ◽  
Vol 9 (3) ◽  
pp. 1051-1062 ◽  
Author(s):  
Andreas Engel ◽  
Harald Bönisch ◽  
Tim Schwarzenberger ◽  
Hans-Peter Haase ◽  
Katja Grunow ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
European Space Agency ◽  
High Spectral Resolution ◽  
Vertical Profiles ◽  
Validation Data ◽  
Data Set ◽  
Mixing Ratios ◽  
Trajectory Matching ◽  
Wide Range ◽  
Resolution Data

Abstract. MIPAS-Envisat is a satellite-borne sensor which measured vertical profiles of a wide range of trace gases from 2002 to 2012 using IR emission spectroscopy. We present geophysical validation of the MIPAS-Envisat operational retrieval (version 6.0) of N2O, CH4, CFC-12, and CFC-11 by the European Space Agency (ESA). The geophysical validation data are derived from measurements of samples collected by a cryogenic whole air sampler flown to altitudes of up to 34 km by means of large scientific balloons. In order to increase the number of coincidences between the satellite and the balloon observations, we applied a trajectory matching technique. The results are presented for different time periods due to a change in the spectroscopic resolution of MIPAS in early 2005. Retrieval results for N2O, CH4, and CFC-12 show partly good agreement for some altitude regions, which differs for the periods with different spectroscopic resolution. The more recent low spectroscopic resolution data above 20 km altitude show agreement with the combined uncertainties, while there is a tendency of the earlier high spectral resolution data set to underestimate these species above 25 km. The earlier high spectral resolution data show a significant overestimation of the mixing ratios for N2O, CH4, and CFC-12 below 20 km. These differences need to be considered when using these data. The CFC-11 results from the operation retrieval version 6.0 cannot be recommended for scientific studies due to a systematic overestimation of the CFC-11 mixing ratios at all altitudes.

scholarly journals High-spectral-resolution attosecond absorption spectroscopy of autoionization in xenon

2014 ◽  
Vol 89 (2) ◽  
Author(s):  
Birgitta Bernhardt ◽  
Annelise R. Beck ◽  
Xuan Li ◽  
Erika R. Warrick ◽  
M. Justine Bell ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Spectral Resolution ◽  
High Spectral Resolution

scholarly journals Room temperature wideband tunable photoluminescence of pulsed thermally annealed layered black phosphorus

Nanophotonics ◽  
2020 ◽  
Vol 9 (14) ◽  
pp. 4253-4264
Author(s):  
Sarah A. Alodan ◽  
Justin M. Gorham ◽  
Frank W. DelRio ◽  
Fadhel Alsaffar ◽  
Ghadeer Aljalham ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Photoelectron Spectroscopy ◽  
Light Emission ◽  
Underlying Mechanism ◽  
Black Phosphorus ◽  
High Spectral Resolution ◽  
Ambient Conditions ◽  
Wide Range ◽  
Thermal Annealing Process ◽  
Tunable Emission

AbstractNewly explored two-dimensional (2D) materials have shown promising optical properties, owning to the tunable band gap of the layered material with its thickness. A widely used method to achieve tunable light emission (or photoluminescence) is through thickness modulation, but this can only cover specific wavelengths. This approach limits the development of tunable optical devices with high spectral resolution over a wide range of wavelengths. Here, we report wideband tunable light emission of exfoliated black phosphorus nanosheets via a pulsed thermal annealing process in ambient conditions. Tunable anisotropic emission was observed between wavelengths of 590 and 720 nm with a spectral resolution of 5 nm. This emission can be maintained for at least 11 days when proper passivation coupled with adequate storage is applied. Using hyperspectral imaging X-ray photoelectron spectroscopy (i-XPS), this tunable emission is found to be strongly dependent on the level of oxidation. We finally discuss the underlying mechanism responsible for the observed tunable emission and show that tunable emission is only observed in nanosheets with thicknesses of (70–125 nm) ± 10 nm with the maximum range achieved for nanosheets with thicknesses of 125 ± 10 nm. Our results shed some light on an emerging class of 2D oxides with potential in optoelectronic applications.

High spectral resolution of diode laser absorption spectroscopy for isotope analysis using a supersonic plasma jet

2018 ◽  
Vol 33 (7) ◽  
pp. 1150-1153 ◽  
Author(s):  
Akira Kuwahara ◽  
Yasuaki Aiba ◽  
Shinya Yamasaki ◽  
Takuya Nankawa ◽  
Makoto Matsui
Keyword(s):  
Diode Laser ◽  
Absorption Spectroscopy ◽  
Spectral Resolution ◽  
Plasma Jet ◽  
High Spectral Resolution ◽  
Laser Absorption Spectroscopy ◽  
Laser Absorption ◽  
Supersonic Plasma ◽  
Diode Laser Absorption ◽  
Supersonic Plasma Jet

The spectral resolution of diode laser absorption spectroscopy is drastically enhanced by applying a supersonic plasma jet to distinguish isotope shifts due to the mass number.

High Performance Photoluminescence Spectroscopy using Fourier Transform Interferometry

1989 ◽  
Vol 163 ◽  
Author(s):  
M.L.W. Thewalt ◽  
M.K. Nissen ◽  
D.J.S. Beckett ◽  
K.R. Lundgren
Keyword(s):  
Fourier Transform ◽  
Spectral Resolution ◽  
High Performance ◽  
Tunable Laser ◽  
High Sensitivity ◽  
Photoluminescence Spectroscopy ◽  
High Spectral Resolution ◽  
Photoluminescence Excitation ◽  
Laser Sources ◽  
Very High

AbstractWe present recent results on the applications of Fourier transform techniques to photoluminescence spectroscopy as it relates to both basic and characterization-related semiconductor research. The emphasis here is on demonstrating the advantages of these methods in situations requiring very high spectral resolution and/or very high sensitivity. We also provide an example of the utility of interferometry in performing photoluminescence excitation spectroscopy in spectral regions where broadly tunable laser sources are not readily available.

scholarly journals Minimum Local Emissivity Variance Retrieval of Cloud Altitude and Effective Spectral Emissivity—Simulation and Initial Verification

2004 ◽  
Vol 43 (5) ◽  
pp. 795-809 ◽  
Author(s):  
Hung-Lung Huang ◽  
William L. Smith ◽  
Jun Li ◽  
Paolo Antonelli ◽  
Xiangqian Wu ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Spectral Resolution ◽  
Single Layer ◽  
Spectral Emissivity ◽  
Pressure Level ◽  
High Spectral Resolution ◽  
Mean Square ◽  
Atmospheric Conditions ◽  
Wide Range ◽  
Mean Square Errors

Abstract This paper describes the theory and application of the minimum local emissivity variance (MLEV) technique for simultaneous retrieval of cloud pressure level and effective spectral emissivity from high-spectral-resolution radiances, for the case of single-layer clouds. This technique, which has become feasible only with the recent development of high-spectral-resolution satellite and airborne instruments, is shown to provide reliable cloud spectral emissivity and pressure level under a wide range of atmospheric conditions. The MLEV algorithm uses a physical approach in which the local variances of spectral cloud emissivity are calculated for a number of assumed or first-guess cloud pressure levels. The optimal solution for the single-layer cloud emissivity spectrum is that having the “minimum local emissivity variance” among the retrieved emissivity spectra associated with different first-guess cloud pressure levels. This is due to the fact that the absorption, reflection, and scattering processes of clouds exhibit relatively limited localized spectral emissivity structure in the infrared 10–15-μm longwave region. In this simulation study it is shown that the MLEV cloud pressure root-mean-square errors for a single level with effective cloud emissivity greater than 0.1 are ∼30, ∼10, and ∼50 hPa, for high (200– 300 hPa), middle (500 hPa), and low (850 hPa) clouds, respectively. The associated cloud emissivity root-mean-square errors in the 900 cm−1 spectral channel are less than 0.05, 0.04, and 0.25 for high, middle, and low clouds, respectively.

scholarly journals A New Algorithm for the Retrieval of Sun Induced Chlorophyll Fluorescence of Water Bodies Exploiting the Detailed Spectral Shape of Water-Leaving Radiance

2021 ◽  
Vol 13 (2) ◽  
pp. 329
Author(s):  
Carolina Tenjo ◽  
Antonio Ruiz-Verdú ◽  
Shari Van Wittenberghe ◽  
Jesús Delegido ◽  
José Moreno
Keyword(s):  
Chlorophyll Fluorescence ◽  
Spectral Resolution ◽  
Optically Active ◽  
High Spectral Resolution ◽  
Support Vector ◽  
Active Constituents ◽  
Wide Range ◽  
Relative Errors ◽  
The One ◽  
Carbon Productivity

Sun induced chlorophyll fluorescence (SICF) emitted by phytoplankton provides considerable insights into the vital role of the carbon productivity of the earth’s aquatic ecosystems. However, the SICF signal leaving a water body is highly affected by the high spectral variability of its optically active constituents. To disentangle the SICF emission from the water-leaving radiance, a new high spectral resolution retrieval algorithm is presented, which significantly improves the fluorescence line height (FLH) method commonly used so far. The proposed algorithm retrieves the reflectance without SICF contribution by the extrapolation of the reflectance from the adjacent regions. Then, the SICF emission curve is obtained as the difference of the reflectance with SICF, the one actually obtained by any remote sensor (apparent reflectance), and the reflectance without SICF, the one estimated by the algorithm (true reflectance). The algorithm first normalizes the reflectance spectrum at 780 nm, following the similarity index approximation, to minimize the variability due to other optically active constituents different from chlorophyll. Then, the true reflectance is estimated empirically from the normalized reflectance at three wavelengths using a machine learning regression algorithm (MLRA) and a cubic spline fitting adjustment. Two large reflectance databases, representing a wide range of coastal and ocean water components and scattering conditions, were independently simulated with the radiative transfer model HydroLight and used for training and validation of the MLRA fitting strategy. The best results for the high spectral resolution SICF retrieval were obtained using support vector regression, with relative errors lower than 2% for the SICF peak value in 81% of the samples. This represents a significant improvement with respect to the classic FLH algorithm, applied for OLCI bands, for which the relative errors were higher than 40% in 59% of the samples.

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