Article
Instruments & Instrumentation
Luca Ciaffoni, Pavel Matousek, William Parker, Elin A. McCormack, Hugh Mortimer
Summary: This study presents a generic analytical model for comparing the detection performance of Raman spectrometers based on grating and spatial heterodyne designs. It shows that the SNR ratio between the two types of spectrometers can vary by two orders of magnitude, with spatial heterodyne spectrometers potentially competing with compact grating designs in delivering comparable detection performance in a much smaller footprint.
APPLIED SPECTROSCOPY
(2021)
Article
Optics
Qihang Chu, Yuqi Sun, Ci Sun, Yu Shuo, Fuguan Jirigalantu, Xiaotian Li, Fuguan Li, Bayanheshig
Summary: This paper proposes a spatial heterodyne Raman spectrometer (SHRS) based on a multi-Littrow-angle multi-grating (MLAMG). Compared with a conventional multi-grating, the MLAMG provides higher spectral resolution and a broader spectral range, and is easier to produce. The experiments demonstrate the significance of MLAMG-SHRS for broadband measurements in various potential applications.
Article
Chemistry, Multidisciplinary
Yuqi Sun, Xiaotian Li, Jiri Galantu, Qihang Chu, Jun Chen, Zhongkai Liu, Xiaotao Mi, Xuefeng Yao, Pan Li
Summary: A method for measuring the terahertz Raman spectra of materials was proposed, utilizing an inexpensive excitation source and detector as an alternative to costly THz equipment. With a resolution of 4.945 cm(-1) and spectral range of 2531.84 cm(-1), the system showed good stability and repeatability, unaffected by interference from the water environment. This method has potential applications in material detection and environmental protection.
APPLIED SCIENCES-BASEL
(2021)
Article
Instruments & Instrumentation
Abigail Waldron, Ashley Allen, Arelis Colon, J. Chance Carter, S. Michael Angel
Summary: The mSHRS is a compact and stable monolithic Raman spectrometer that offers high spectral resolution and high light throughput.
APPLIED SPECTROSCOPY
(2021)
Article
Spectroscopy
K. Alicia Strange Fessler, Abigail Waldron, Arelis Colon, J. Chance Carter, S. Michael Angel
Summary: Three spatial heterodyne Raman spectrometers, including one free standing and two monolithic, were utilized for remote Raman and LIBS testing on samples at different distances, as well as 1D Raman imaging. The study demonstrated that using large laser spots can reduce sample photodegradation during Raman testing, while 1D imaging provides better signal-to-noise ratio spectra.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2021)
Article
Optics
Qihang Chu, Xiaotian Li, Jirigalantu, Ci Sun, Jun Chen, Jianing Wang, Yuqi Sun, Bayanheshig
Summary: This paper presents a cross-dispersed spatial heterodyne spectrometer (CDSHS) that combines a spatial heterodyne spectrometer (SHS), a reflection grating, and a cylindrical lens. It provides expressions for the width, height, and location of the cross-dispersed interferograms corresponding to narrow spectral regions. A design example of CDSHS, including numerical simulations of the interferogram and the spectrum, is provided to illustrate the system. The results demonstrate that the CDSHS can simultaneously disperse different narrow spectral regions and obtain detailed spectra independently with a high signal-to-noise ratio, while maintaining advantages such as high resolution, high throughput, compactness, and zero moving parts. The CDSHS has great potential in applications such as multiple spectral feature measurement and weak spectral measurements.
Article
Instruments & Instrumentation
Evan M. Kelly, Miles J. Egan, Arelis Colon, S. Michael Angel, Shiv K. Sharma
Summary: This paper presents a remote Raman spectrometer based on single-grating monolithic SHRS, which has a large spectral range, high resolution, low alignment sensitivity, and high light throughput. It is a promising candidate for planetary exploration.
APPLIED SPECTROSCOPY
(2023)
Article
Optics
Qihang Chu, Xiaotian Li, Yuqi Sun, Jirigalantu, Ci Sun, Jun Chen, Fuguan Li, Bayanheshig
Summary: This paper introduces a multi-grating-based spatial heterodyne spectrometer (MGCDSHS). The principle and equations for generating interferograms in two cases, where the light beam is diffracted by one or two sub-gratings, are given. Numerical simulations of the instrument design demonstrate its ability to record simultaneous interferograms corresponding to different spectral features with high resolution over a broad spectral range. The compact and stable MGCDSHS solves mutual interference and throughput loss problems, making it suitable for high-sensitivity, high-resolution, and broadband spectral measurements.
Article
Chemistry, Multidisciplinary
Yuqi Sun, Xiaotian Li, Jiri Galantu, Qihang Chu, Jun Chen, Fuguan Li, Nan Song, Geng Wang, Qiliang Ni
Summary: This paper presents the development of an echelle grating spatial heterodyne terahertz Raman spectrometer (E-SHTRS) that combines echelle gratings with spatial heterodyne terahertz Raman spectroscopy. The system achieves higher spectral resolution and a wider detection range compared to conventional spectrometers. Experimental results demonstrate the good detection performance and potential applications of the E-SHTRS in various fields.
APPLIED SCIENCES-BASEL
(2023)
Article
Instruments & Instrumentation
Evan M. Kelly, Miles J. Egan, Arelis Colon, S. Michael Angel, Shiv K. Sharma
Summary: This study investigates the impact of different types of cameras (CCD, ICCD, and CMOS) on the performance of the 1g-mSHRS system. The results show that increasing the number of pixels along the X-axis improves fringe visibility and resolution, while the number of pixels along the Y-axis, chip size, and dimensions affect the signal-to-noise ratio.
APPLIED SPECTROSCOPY
(2023)
Article
Chemistry, Analytical
Yunfei Bai, Haiyan Luo, Zhiwei Li, Yi Ding, Yunfei Han, Wei Xiong
Summary: Spatial heterodyne Raman spectroscopy combined with chemometric methodologies was used to quantitatively analyze mixtures. Variational mode decomposition and chemometric methods improved the prediction accuracy, and support vector regression showed the best predictive performance among the tested models.
ANALYTICAL LETTERS
(2023)
Article
Instruments & Instrumentation
Miles J. Egan, Arelis M. Colon, S. Michael Angel, Shiv K. Sharma
Summary: Spatial heterodyne spectrometers are known for their ability to acquire high-resolution emission spectra in compact designs, but their sensitivity is limited by multiplicative photon noise. This study introduces a novel coupling method with an Amici prism spectrometer to suppress multiplicative noise and enable the measurement of weak Raman spectral features that would have been washed out by traditional spatial heterodyne spectrometers.
APPLIED SPECTROSCOPY
(2021)
Article
Optics
M. G. Burke, R. J. Fonck, J. M. Harlander, G. R. McKee
Summary: A broadening compensation method was developed for spatial heterodyne spectroscopy interferometric technique to reduce artificial broadening and enable high resolution measurements at a significantly higher photon flux. The compensated measurement of emission from deuterium neutrals in a tokamak plasma showed a spectral width of about 0.13 nm, 4 times smaller than the uncompensated width of 0.5 nm.
Article
Spectroscopy
Qingsheng Xue, Nan Wang, Hui Yang, Jingyao Yang, Haoxuan Bai
Summary: In this study, a method combining Spatial heterodyne technology and Raman spectroscopy was proposed for rapid, efficient, and accurate detection of microplastics. By building a spatial heterodyne spectrometer and an optical system, detection and identification of different types of microplastic samples were achieved. The results showed a higher signal-to-noise ratio with this method, indicating its good performance and potential in the field of microplastics detection.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Chemistry, Physical
Tong Zhang, Zhi-Chao Huangfu, Yuqin Qian, Zhou Lu, Hong Gao, Yi Rao
Summary: In this work, broadband heterodyne detection was used to study the frequency-dependent spectral phases in interfacial electronic spectroscopy. It was found that the often-used Au thin film is not a suitable reference for frequency-dependent phases.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
