Resolution Spectrometer Research Articles

High-resolution multi-scan compact Fourier transform-infrared spectrometer.

The Fourier transform-infrared (FT-IR) spectrometer is a widely used high-resolution spectral characterization method in materials, chemicals, and more. However, the inverse relation between the spectral resolution and the interferometer's arm length yields a tradeoff between spectral resolution and spectrometer footprint. Here, we introduce a novel method to overcome this traditional FT-IR resolution limit. The enhanced high-resolution multi-scan compact FT-IR spectrometer we present achieves an effectively long interferogram by combining multiple short FT-IR scans. Simulation and experimental results demonstrate a significant increase in the spectral resolution of a FT-IR spectrometer by employing our interferogram stitching algorithm.

On-chip interrogator based on Fourier transform spectroscopy.

In this paper, the design and the characterization of a novel interrogator based on integrated Fourier transform (FT) spectroscopy is presented. To the best of our knowledge, this is the first integrated FT spectrometer used for the interrogation of photonic sensors. It consists of a planar spatial heterodyne spectrometer, which is implemented using an array of Mach-Zehnder interferometers (MZIs) with different optical path differences. Each MZI employs a 3×3 multi-mode interferometer, allowing the retrieval of the complex Fourier coefficients. We derive a system of non-linear equations whose solution, which is obtained numerically from Newton's method, gives the modulation of the sensor's resonances as a function of time. By taking one of the sensors as a reference, to which no external excitation is applied and its temperature is kept constant, about 92% of the thermal induced phase drift of the integrated MZIs has been compensated. The minimum modulation amplitude that is obtained experimentally is 400 fm, which is more than two orders of magnitude smaller than the FT spectrometer resolution.

Detection of sodium aerosol using laser induced breakdown spectroscopy

Analysis of sodium aerosol is very important in various field including nuclear power station, electronic industry, and medical field. In medical field, aerosol detection can be employed to earlier detection of disease based on liquid in human being. In this present work, aerosol sodium detection has been performed using laser-induced breakdown spectroscopy (LIBS) utilizing pulse Nd:YAG laser. In the study, sodium aerosol made of sodium chloride (NaCl) liquid was deposited on a copper (Cu) metal plate. The Cu plate functions as a metal subtarget to initiate a plasma emission and to improve the emission intensity of sodium line. Experimentally, a pulse laser Nd YAG (1064 nm, 7 ns, dan 45 mJ) was focused on a sodium aerosol to induce a luminous plasma. The plasma was then sent into the spectrometer to obtain the emission spectrum of sodium. The observed sodium aerosol samples were made in five variations based on their various molarities (concentrations). Variations are made, ranging from 1 molar to 3 molar with the difference of each sample of 0.5 molar. Sharp Na lines at 588.9 nm and 589.3 nm, which overlap due to low resolution of spectrometer were clearly detected. The other lines coming from Cu subtarget occurs at 324.7 nm and 327.4 nm. Detail study of sodium analysis using laser induced breakdown spectroscopy will be presented.

Pyrolitic Graphite Mosaic Crystal Thickness and Mosaicity Optimization for an Extended Source Von Hamos X-ray Spectrometer

Bragg spectroscopy, one of the best established experimental techniques for high energy resolution X-ray measurements, has always been limited to the measurement of photons produced from well collimated (tens of microns) or point-like sources; recently, the VOXES collaboration at INFN National Laboratories of Frascati developed a prototype of a high resolution and high precision X-ray spectrometer working also with extended isotropic sources. The realized spectrometer makes use of Highly Annealed Pyrolitic Graphite (HAPG) crystals in a “semi”-Von Hamos configuration, in which the position detector is rotated with respect to the standard Von Hamos one, to increase the dynamic energy range, and shows energy resolutions at the level of 0.1% for photon energies up to 10 keV and effective source sizes in the range 400–1200 μ m in the dispersive plane. Such wide effective source dimensions are achieved using a double slit system to produce a virtual point-like source between the emitting target and the crystal. The spectrometer performances in terms of reflection efficiency and peak resolution depend on several parameters, among which a special role is played by the crystal mosaicity and thickness. In this work, we report the measurements of the Cu(K α 1 , 2 ) and the Fe(K α 1 , 2 ) lines performed with different mosaicity and thickness crystals in order to investigate the influence of the parameters on the peak resolution and on the reflection efficiency mentioned above.

Simultaneous Cr(VI) reduction and Cr(III) removal of bifunctional MOF/Titanate nanotube composites

In this study, a series of BUC-21/titanate nanotube (BT-X) composites were facilely fabricated via ball-milling of 2-dimensional (2D) metal-organic framework (MOF) BUC-21 and titanate nanotubes (TNTs). The BT-X composites were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), UV-visible diffuse-reflectance spectroscopy (UV-vis DRS), X-ray photoelectron spectrometer (XPS) and high resolution transmission electron microscopy (HRTEM). Both the photocatalytic reduction from Cr(VI) to Cr(III) and adsorptive removal of formed Cr(III) of BT-X composites were systematically investigated under different conditions including pH values and co-existing inorganic ions. It was found that BUC-21 (100 mg)/TNTs (100 mg) (BT-1) composites demonstrate remarkable ability of photocatalytic Cr(VI) reduction and adsorptive Cr(III) removal, as well as good reusability and stability. It is believed that the introduction of TNTs could capture the formed Cr(III) from the surface of BUC-21, which provided more active sites exposed to enhance the Cr(VI) reduction.

A Thin-foil Proton Recoil spectrometer for DT neutrons using annular silicon detectors

The use of Thin-foil Proton Recoil (TPR) spectrometers to measure neutrons from Deuterium-Tritium (DT) fusion plasma has been studied previously and is a well established technique for neutron spectrometry. The study presented here focuses on the optimisation of the TPR spectrometer configurations consisting of Δ E and E silicon detectors. In addition an investigation of the spectrometer's ability to determine fuel ion temperature and fuel ion density ratio in ITER like DT plasmas has been performed.A Python code was developed for the purpose of calculating detection efficiency and energy resolution as a function of several spectrometer geometrical parameters. An optimisation of detection efficiency for selected values of resolution was performed regarding the geometrical spectrometer parameters using a multi-objective optimisation, a.k.a. Pareto plot analysis. Moreover, the influence of detector segmentation on spectrometer energy resolution and efficiency was investigated. The code also produced response functions for the two selected spectrometer configurations. The SPEC code was used to simulate the spectrometer's performance in determining the fuel ion temperature and fuel ion density ratio nt/nd.The results presented include the selected spectrometer configuration with calculated energy resolution and efficiency. For a selected spectrometer resolution of 5% a maximum efficiency of around 0.003% was achieved. Moreover, the detector segmentation allows for a 20% increase in spectrometer efficiency for an energy resolution of 4.3%. The ITER requirements for a 20% accuracy on the nt/nd ratio determination and 10% on the temperature determination within a 100 ms sampling window can be achieved using a combination of several TPR's of same type, in order to boost efficiency.

Construction of Ir-Co/C nanocomposites and their application in ammonia oxidation reaction

Ammonia electro-oxidation reaction has been paid much attention in recent years because it is widely used in various fields. However, the electro-oxidation of ammonia is a complex process, especially the reaction intermediate has a slow toxic effect on the electrode. To reduce the catalyst poisoning by the absorption of intermediate, the constituent and structure of the catalysts must be deeply researched. In this work, carbon-supported Ir-Co alloy nanocomposites were prepared by pre-deposited method. X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and high resolution transmission electron microscopy (HRTEM) were used to measure the character of the nanocomposites. As expected, the Ir-Co/C nanocomposites revealed superior electro-catalytic activity towards the oxidation of ammonia in 0.4M NaClO4 solution. The Ir-Co/C-modified GCE demonstrated high sensitivity for ammonia from a range of 0–2.5M when using amperometry technique to simulate the ammonia-detected environment. At last, real sensor analysis was served to investigate the ammonia-detected performance of the Ir-Co/C, demonstrating high sensitivity and quick response compare to Ir/C and commercial Pt-Ru/C.

Subnanometer optical linewidth of thulium atoms in rare-gas crystals

We investigate the 1140 nm magnetic dipole transition of thulium atoms trapped in solid argon and neon. These solids can be straightforwardly grown on any substrate at cryogenic temperatures, making them prime targets for surface sensing applications. Our data are well described by a splitting of the single vacuum transition into three components in both argon and neon, with each component narrower than the 0.8 nm spectrometer resolution. The lifetime of the excited states is 14.6(0.5) ms in argon and 27(3) ms in neon, shorter than in vacuum or in solid helium. We also collected visible laser-induced fluorescence spectroscopy showing broader emission features in the range of 580-600 nm. The narrow infrared features in particular suggest a range of possible applications.

CONCENTRATION OF ALUMINUM, IRON AND MANGANESE IN URBAN RIVERS LOCATED IN A COVERAGE AREA OF THE GUARANI AQUIFER IN LAGES - SC

The objective of the current study was to evaluate the concentration of aluminum (Al), iron (Fe) and manganese (Mn) on water and on the sediment of urban rivers (Carahá, Caveiras and Ponte Grande) in Lages, located on the mountain region of Santa Catarina, placed in a coverage area of the Guarani Aquifer. The water and sediment samples were collected between May and October of 2016 in three urban rivers, following an environmental disturbance gradient. For the extraction of the metals present on the sample, it was used the methods 3030 - Standard Methods of Water and Wastewater (2005) for the water samples and ISO 11,466 (1995) for the sediment samples. The quantification of metals was performed through a high- resolution spectrometer with atomic absorption, with a flame automation (acetylene-air or nitrous oxide-air). To evaluate the quantification, it was used a certified material (SRM 2709a - San Joaquin Soil - NIST). On the water samples were found concentrations of Mn above of class III, defined by the Resolution 357/05 of the Environment National Board-Brazil. The Pearson correlation matrix showed a positive correlation between the variables Al/Fe, Fe/Mn e Al/Mn on sediment and Fe/Mn on water. For the sediment, it was found high concentrations of Al, Fe, and Mn in some of the samples. By the results found, it is evinced an increase in the concentration of Al and Fe on the Carahá river sediment, and concentrations of Al, Fe, and Mn on the Ponte Grande river sediment, on the spots located at Lages - SC.

Novel reference-free methods for the determination of the instrumental response of Laue-type bent crystal spectrometers

This paper presents two novel reference-free methods for the determination of the instrumental resolution of Laue-type crystal spectrometers.

Estimation of the spectral resolution of an imaging spectrometer from Fraunhofer's lines with the MODTRAN atmospheric model

Estimation of the spectral resolution of an imaging spectrometer from Fraunhofer's lines with the MODTRAN atmospheric model

Testing of MAES analyzers with BLPP-2000 and BLPP-4000 photodetector linear arrays in a “GRAND-POTOK” spectral system

For the development of “Grand-Potok” spectral systems and rapid high-sensitivity scintillation atomic emission spectrometry, the “VMK-Optoelektronika” company created a new BLPP-2000 photodetector linear array. Testing of the array as part of “Grand-Potok” spectral system had shown its advantages over a BLPP-369М1 array in recording scintillations of the gold Au 267.595 nm analytical spectral line. Further studies of the BLPP-2000 detector revealed the need to increase the spectral resolution of the system. For this, a new BLPP-4000 photodetector linear array has been developed. It was expected that its use would improve the resolution of the Grand spectrometer over the entire wavelength range, but a reduction in the sensitivity of the spectrometer could be possible. The objectives of this study were to experimentally compare the resolution and signal-to-noise ratio of the “Grand-Potok” spectral system using BLPP-2000, BLPP-4000, and BLPP-369М1 photodetector linear arrays and contrast the obtained results with the characteristics of the higher-resolution Grand-1500 spectrometer with BLPP-2000, which had shown good performance in determination of noble metals in geological samples with complex matrix. The data on the intensities and widths of the spectral lines were obtained from the spectra of the standard samples of various compositions and used to compare the signal-to-noise ratio and spectral resolution of the systems. The study showed that the use of the new MAES analyzers based on BLPP-4000 linear photodetector arrays in the Grand spectrometer increased the resolution of the instrument by a factor of two, while the signal-to-noise ratio of the instrument decreased by a factor of 4-6, leading to the deterioration of the detection limits in the scintillation arc atomic-emission spectrometry. Nevertheless, Grand spectrometers based on BLPP-4000 could be used instead of higher-resolution Grand-1500 spectrometers without deterioration of the detection limits as its aperture is 5–20 times higher. In addition, the signal-to-noise ratio and the resolution in Grand spectrometers with BLPP-369M1 detector arrays used in analytical laboratories could be increased by replacing the detectors with BLPP-4000 arrays. Keywords: Grand-Potok spectral system, MAES high-speed analyzer, spectral resolution, geological samples, scintillation atomic emission spectrometry (Russian) DOI: http://dx.doi.org/10.15826/analitika.2019.23.1.005 A.A. Dzyuba 1,2 , V.A. Labusov 1,2,3 , and S.A. Babin 1,2 1 Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, pr. Akademika Koptyuga, 1, Novosibirsk, 630090, Russian Federation 2 VMK-Optoelektronika, pr. Akademika Koptyuga, 1, Novosibirsk, 630090, Russian Federation 3 Novosibirsk State Technical University, pr. K. Marksa, 20, Novosibirsk, 630073, Russian Federation

СПОСОБЫ УЛУЧШЕНИЯ ХАРАКТЕРИСТИК СПЕКТРОМЕТРОВ ВЫСОКОГО РАЗРЕШЕНИЯ

The present paper demonstrates results of high-resolution spectrometer characteristics improvement methods. Increasing resolution, spectral range extending and illumination efficiency for the spectrometer were investigated. Obtained results will be found useful in atomic spectroscopy applications such as atomic absorption, atomic emission spectroscopy, mass-spectroscopy, chromatography and others. In order to increase spectrometer resolution it was suggested to use higher diffractive grating curvature radius. Experimentally, characteristics of both spectrometer prototypes assembled using diffractive gratings R1000 and R2000 were obtained and compared. New approach for polychromatous displacement was developed in order to extend operational spectrum range. The main feature is single spectrometer entrance slit for both UV and visible range Paschen-Runge polychromatous with beam splitting by coupled flat folding mirrors placed behind slit. Diffractive grating illumination monitor system was designed in order to provide this spectrometer by alignment control for lightning system. New spectrometer “Grand-2” was fabricated. It includes coupled Paschen-Runge polychromators for UV and visible spectral range providing 12 and 30 pm spectral resolution respectively with single entrance slit equipped with diffractive grating illumination monitoring system. This spectrometer can be used for various atomic spectroscopy applications.

Increasing of Spectral Resolution of Multislit Imaging Spectrometer with Diffractive Grating

Registration of non-stationary processes, namely snapshot hyperspectral imaging that allows to capture data cube I ( x , y ,λ) in one measurement act, is of interest for imaging spectroscopy. The purpose of the work is increasing of spectral resolution of imaging spectrometers with spatial filtering of object image using multislit mask, where a diffractive grating is used as disperser (providing almost constant dispersion in working spectral range), and the data cube is projected on a detector as a set of local spectra from object fragments. An image is formed on detector by a two-objective telecentric system composed from two lenses focused on infinity so that their front focuses are matched. A diaphragm in the match point allows passing only for beams of needed diffraction order, so along with a bandpass filter near the system entrance they solve a typical problem of diffractive systems – elimination of beams of all orders but a needed one. The approach is implemented in two proposed designs of spectrometers: in the first a telecentric system is based on two multi-lens imaging objectives, in the second – is based on two reflective off-axis parabolic objectives. In this paper we proposed variants for optical design optimization: normalization of beam incidence on a mask and field curvature compensation; they allow to increase system resolution and to extend application area of multislit dispersive spectrometers; also a design being a synthesis of these two approaches is analyzed. According to simulation results, width on half-maximum in dispersion direction Δ l ≤ 10 µm, only for limited field points set Δ l ≤ 15 µm, that stands for spectral resolutio

Compact Aberration‐Corrected Spectrometers in the Visible Using Dispersion‐Tailored Metasurfaces

AbstractThe spectral resolution and range of conventional spectrometers are typically limited by optical aberrations of their focusing elements, mainly due to chromatically induced astigmatism and an intrinsically curved focal plane. Traditional approaches to overcome this challenge require additional optical components which introduce significant bulk and design complexity to the system and prevent easy integration with portable devices. Here a single planar off‐axis focusing metalens consisting of subwavelength TiO2 nanofins whose focal spots lie along a plane and undergo minimal focal spot broadening for almost 200 nm across the visible spectrum is demonstrated. This allows us to achieve a miniature aberration‐corrected spectrometer with nanometer spectral resolution, while having a beam propagation distance of only 4 cm to the camera plane. This is achieved by dispersion engineering: tailoring the phase, group delay (GD) and GD dispersion of the metalens. This approach is general and can also be used to introduce customized functionalities to the metalens such as a linear dispersion in the frequency domain with minimal additional overhead.

Improved photocatalytic performance of flower-like BiOBr/BiOCl heterojunctions prepared by an ionic liquid assisted one-step hydrothermal method

Construction of heterojunctions is a promising and solid strategy to tune the photocatalytic performance of BiOCl. In this work, flower-like BiOBr/BiOCl heterojunctions (IL-BiOCl) was in situ prepared by N-ethylpyridinium bromide ([BPy]Br) assisted one-step hydrothermal method. The samples were studied by a serials method. The results exhibit that [BPy]Br promotes the specific surface area and the separation rate of photoinduced carriers. Energy dispersive spectrometer (EDS) and high resolution transmission electron microscopy (HRTEM) results firmly reveal that BiOBr/BiOCl heterojunctions were successfully constructed. [BPy]Br provides Br source for BiOBr and influences the shape of the IL-BiOCl. Photocatalytic activity of the samples were evaluated, the results reveal that IL-BiOCl possesses higher photocatalytic activity than BiOCl toward decomposition of rhodamine B (RhB) under simulated sunlight irradiation.

Heasim and skyback simulation tools and their application to the Hitomi mission

We present an introduction to the heasim multimission observation and skyback background, high-energy pseudo Monte Carlo astrophysical simulation tools. Heasim may be used to accurately and efficiently construct flexible image transport system (FITS) event files for simple or composite sources with a wide range of standard and user-defined spatial, spectral, and temporal characteristics. Skyback is designed to enable users to assess the impact of background discrete and diffuse emission on prospective observations, and skyback output may be directly input into heasim. We present a brief overview of heasim and skyback input, algorithms, usage, and output. We also introduce the sxsbranch tool that computes Hitomi soft X-ray spectrometer resolution grade branching ratios, emphasizing its application to simulations. We include several examples of particular relevance to the Hitomi mission.

Optical Efficiency and Spectral Resolution of the Grand, Grand-1500, and STE-1 Spectrometers

For comparing the characteristics of the Grand, Grand-1500, and STE-1 spectrometers, which are used as a part of a scintillation atomic emission complex in a combination with an electric arc setup Potok for analysis of powdered samples by the spillage-injection method, their optical efficiency, reciprocal linear dispersion, and spectral resolution are measured in the 235–344 nm region. The spectral resolution of the Grand-1500 spectrometer is 1.5–2 times better than that of the other studied spectrometers. The resolution of the Grand and STE-1 spectrometers in the fifth diffraction order is practically the same, whereas in the fourth order the resolution of the Grand is significantly better. In the 240–270 nm region, the optical efficiency of the Grand exceeds that of the STE-1 by an order of magnitude, and by a factor of 4 in the 342 nm range. The optical efficiency of the Grand-1500 near 240 nm is slightly higher than of the STE-1, whereas at 267 and 342 nm it exceeds it by a factor of 2 and 5, respectively.

Fabrication of a high-resolution smartphone spectrometer for education using a 3D printer

In this paper, we present the details of the development of a smartphone spectrometer for education using a 3D printer and characterized the performance by comparison with a paper craft spectrometer. The optical design and the narrow slit used in the build resulted in the formation of accurate images of the slit on the image sensor leading to a superior resolution compared to the paper craft spectrometer. The measured spectral resolution of the 3D-printed smartphone spectrometer was 0.4 nm, which was narrower than those of other smartphone spectrometers. Increasing the exposure time of the phone’s camera revealed the fine structure of a spectrum with high resolution. The baffle structure inside the spectrometer proved to be effective in removing noise when the exposure time was increased. We expect the 3D-printed smartphone spectrometer proposed in this paper can be useful as an education tool for students to understand the various aspects of light, atoms, chemistry, and physics.

Parameters governing the performance of electrical mobility spectrometers for measuring sub-3 nm particles

Measuring aerosol size distributions accurately down to ~1 nm is a key to nucleation studies, and it requires developments and improvements in instruments such as electrical mobility spectrometers in use today. The key factors characterizing the performance of an electrical mobility spectrometer for sub-3 nm particles are discussed in this study. A parameter named as Π is proposed as a figure of merit for the performance of an electrical mobility spectrometer in the sub-3 nm size range instead of the overall detection efficiency. Π includes the overall detection efficiency, the measurement time in each size bin, the aerosol flow rate passing through the detector, and the aerosol-to-sheath flow ratio of the differential mobility analyzer. The particle raw count number recorded by the detector can be estimated using Π at a given aerosol size distribution function, dN/dlogdp. The limit of detection for the spectrometer and the statistical uncertainty of the measured aerosol size distribution can also be readily estimated using Π. In addition to Π, the size resolution of an electrical mobility analyzer is another factor characterizing the systematic errors originated from particle sizing. Four existing electrical mobility spectrometers designed for measuring sub-3 nm aerosol size distributions, including three scanning/differential mobility particle spectrometers and one differential mobility analyzer train, are examined. Their optimal performance is evaluated using Π and the size resolution. For example, the Π value and the size resolution of a diethylene-glycol differential mobility particle spectrometer for 1.5 nm particles are 8.0 × 10−4 cm3 and 5.7, respectively. The corresponding relative uncertainty of the measured size distribution is approximately 9.6% during an atmospheric new particle formation event with a dN/dlogdp of 5 × 105 cm−3. Assuming an adjustable sheath flow rate of the differential mobility analyzer, the optimal size resolution is approximately 5–9 when measuring atmospheric new particle formation events.