Resolved discrepancies between visible spontaneous Raman cross-section and direct near-infrared Raman gain measurements in TeO2-based glasses

Abstract Purpose The purpose of this study was to assess whether the vascularisation of the meniscus could be visualised intra-operatively using near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) in patients undergoing total knee arthroplasty (TKA). Methods The anterior horn (i.e., Cooper classification: zones C and D) of the meniscus that was least affected (i.e., least degenerative) was removed during TKA surgery in ten patients to obtain a cross section of the inside of the meniscus. Thereafter, 10 mg of ICG was injected intravenously, and vascularisation of the cross section of the meniscus was assessed using the Quest spectrum NIRF camera system. We calculated the percentage of patients in whom vascularisation was observed intra-operatively using NIRF imaging compared to immunohistochemistry. Results Meniscal vascularisation using NIRF imaging was observed in six out of eight (75%) patients in whom vascularisation was demonstrated with immunohistochemistry. The median extent of vascularisation was 13% (interquartile range (IQR) 3–28%) using NIRF imaging and 15% (IQR 11–23%) using immunohistochemistry. Conclusion This study shows the potential of NIRF imaging to visualise vascularisation of the meniscus, as vascularisation was observed in six out of eight patients with histologically proven meniscal vascularisation. Level of evidence IV.

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Steady-state Raman gain in visible and near-infrared waveband of SrWO4 and BaWO4 crystals

Chinese Optics Letters ◽

10.3788/col201412.121902 ◽

2014 ◽

Vol 12 (12) ◽

pp. 121902-121904 ◽

Cited By ~ 1

Author(s):

Fang Zhang Fang Zhang ◽

Qinghua Zhang Qinghua Zhang ◽

Bo Wang Bo Wang ◽

Dawei Hu Dawei Hu ◽

Haohai Yu Haohai Yu ◽

...

Keyword(s):

Steady State ◽

Near Infrared ◽

Raman Gain

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Crystal growth, structure and characterization of Er6B4O15as self-activated eye-safe laser material within the near-infrared waveband

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520618001488 ◽

2018 ◽

Vol 74 (2) ◽

pp. 132-136

Author(s):

Yan Wang ◽

Wei Zhang ◽

Ziyi Li ◽

Jianfu Li ◽

Zhaojie Zhu ◽

...

Keyword(s):

Cross Section ◽

Fluorescence Spectra ◽

Near Infrared ◽

Emission Cross Section ◽

Fluorescence Decay ◽

X Ray Diffraction ◽

Infrared Wavelength ◽

Rare Earth Borate ◽

Laser Diode Pumping

A new rare-earth borate Er6B4O15was synthesized by a solid-state reaction technique. The crystal was obtained by a flux method. Single-crystal X-ray diffraction analysis revealed that the crystal structure is composed of ErO6polyhedra sharing edges and BO3groups. The absorption, near-infrared fluorescence spectra and the fluorescence decay curve of Er:4I13/2energy level in the Er6B4O15crystal were measured at room temperature. The absorption peak was located at 977 nm with absorption cross section of 1.16 × 10−21 cm2and a full width at half-maximum (FWHM) of 16 nm, which is very suitable for commercial 980 nm laser diode pumping. A maximum emission peak at 1560 mm with a broad FWHM of 64 nm was observed in this crystal because of the Er3+transition4I13/2→4I15/2, while the emission cross section was calculated to be 8.53 × 10−20 cm2. These results imply that the Er6B4O15crystal is a promising candidate material for the achievement of an eye-safe near-infrared wavelength laser.

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Three-Photon Induced Optical Limiting of a Novel Multibranched Nonlinear Chromophore Containing Carbazole Moiety

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.2851 ◽

2012 ◽

Vol 170-173 ◽

pp. 2851-2854 ◽

Cited By ~ 1

Author(s):

Zhi Yuan Hu ◽

Fu Quan Guo ◽

Bin Guo ◽

Hao Liang

Keyword(s):

Cross Section ◽

Near Infrared ◽

Optical Power ◽

Picosecond Laser ◽

Infrared Region ◽

Photon Absorption ◽

Picosecond Laser Pulse ◽

Transmission Measurements ◽

Near Infrared Region ◽

Optical Power Limiting

A novel multibranched nonlinear chromophore containing carbazole moiety，4, 4´, 4´´-tris(9-(3,6-tert-butyl)carbazyl-trans-styryl) -1, 3, 5-triphenylbenzene (TCSTPB)，was synthesized and characterized by 1HNMR and elemental analysis. One-photon absorption in chloroform shows the optical transparent property of the chromophore in the near infrared region. The properties of optical power limiting induced by three-photon absorption (3PA) are demonstrated. Large 3PA coefficients and the corresponding 3PA molecular cross section as high as 10-74 cm6 s2 was obtained pumped by picosecond laser pulse at 1.06 μm from nonlinear transmission measurements.

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Searching for water ice in the coma of interstellar object 2I/Borisov

Astronomy and Astrophysics ◽

10.1051/0004-6361/201937129 ◽

2020 ◽

Vol 634 ◽

pp. L6 ◽

Cited By ~ 7

Author(s):

Bin Yang ◽

Michael S. P. Kelley ◽

Karen J. Meech ◽

Jacqueline V. Keane ◽

Silvia Protopapa ◽

...

Keyword(s):

Solar System ◽

Cross Section ◽

Near Infrared ◽

Chemical Processes ◽

Spectral Slope ◽

Water Ice ◽

Extrasolar Systems ◽

Physical And Chemical ◽

Absorption Features ◽

Rare Opportunity

Aims. Interstellar objects passing through our Solar System offer a rare opportunity to probe the physical and chemical processes involved in solid body and planet formation in extrasolar systems. The main objective of our study is to search for diagnostic absorption features of water ice in the near-infrared (NIR) spectrum of the second interstellar object 2I/2019 Q4 (Borisov) and compare its ice features to those of the Solar System icy objects. Methods. We observed 2I in the NIR on three separate occasions. The first observation was made on 2019 September 19 UT using the SpeX spectrograph at the 3m IRTF and again on September 24 UT with the GNIRS spectrograph at the 8m GEMINI telescope; the last observation was made on October 09 UT with IRTF. Results. The spectra obtained from all three nights appear featureless. No absorption features associated with water ice are detected. Spectral modeling suggests that water grains, if present, comprise no more than 10% of the coma cross section. The comet consistently exhibits a red D-type like spectrum with a spectral slope of about 6% per 1000 Å, which is similar to that of 1I/’Oumuamua and is comparable to Solar System comets.

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Mixed Halide Bulk Perovskite Triplet Sensitizers: Interplay between Band Alignment, Mid-gap Traps and Phonons

10.33774/chemrxiv-2021-vvq4r ◽

2021 ◽

Author(s):

Alexander Bieber ◽

Zachary VanOrman ◽

Hayley Drozdick ◽

Rachel Weiss ◽

Sarah Wieghold ◽

...

Keyword(s):

Cross Section ◽

Absorption Cross Section ◽

Near Infrared ◽

Band Alignment ◽

Absorption Cross ◽

Lead Iodide ◽

Efficient Charge ◽

Halide Perovskites ◽

The Impact ◽

High Absorption

Photon upconversion, particularly via triplet-triplet annihilation (TTA), could prove beneficial in expanding the efficiencies and overall impacts of optoelectronic devices across a multitude of technologies. The recent development of bulk metal halide perovskites as triplet sensitizers is one potential step toward the industrialization of upconversion-enabled devices. Here, we investigate the impact of varying additions of bromide into a lead iodide perovskite thin film on the TTA upconversion process in the annihilator molecule rubrene. We find an interplay between the bromide content and the overall device efficiency. In particular, a higher bromide content results in higher internal upconversion efficiencies, enabled by more efficient charge extraction at the interface, likely due to a more favorable band alignment. However, the external upconversion efficiency decreases, as the absorption cross section in the near infrared is reduced. The highest upconversion performance is found in our study for a bromide content of 5%. This result can be traced back to a high absorption cross section in the near infrared and higher photoluminescence quantum yield in comparison to the iodide-only perovskite, as well as an increased driving force for charge transfer.

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Dust specific extinction cross-sections over the Eastern Mediterranean using the BSC-DREAM model and sun photometer data: the case of urban environments

Annales Geophysicae ◽

10.5194/angeo-27-2903-2009 ◽

2009 ◽

Vol 27 (7) ◽

pp. 2903-2912 ◽

Cited By ~ 22

Author(s):

E. Gerasopoulos ◽

P. Kokkalis ◽

V. Amiridis ◽

E. Liakakou ◽

C. Perez ◽

...

Keyword(s):

Boundary Layer ◽

Cross Section ◽

Near Infrared ◽

Fine Particles ◽

Eastern Mediterranean ◽

Urban Pollution ◽

Wavelength Dependence ◽

Infrared Band ◽

Extinction Cross Section ◽

Sun Photometer

Abstract. In this study, aerosol optical depth (AOD) measurements, from a MFR sun photometer operating in Athens, were compared with columnar dust loading estimations, from the BSC-DREAM model, during identified dust events, in order to extract the typical specific extinction cross-section for dust over the area. The selected urban environment of Athens provided us with the opportunity to investigate the mixing of dust and urban pollution and to estimate the contribution of the latter. The specific extinction cross-section for dust at 500 nm was found to be equal to σ500*=0.64±0.04 m2 g, typical for medium to large distances from dust sources, with weak wavelength dependence in the visible and near infrared band (0.4–0.9 μm). The model showed a tendency to underpredict AOD levels for increasing values of the Ångström exponent, indicative of fine particles of anthropogenic origin inside the boundary layer. On average we found an AOD under-prediction of 10–15% for Ångström exponents in the range of 0 to 1 and 30–40% in the range of 1 to 2. Additionally, modelled surface concentrations were evaluated against surface PM10 measurements. Model values were lower than measured surface concentrations by 30% which, in conjunction with large scatter, indicated that the effect of the boundary layer anthropogenic contribution to columnar dust loadings is amplified near the ground.

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Spectral Range and Wood Surface Impacts on Equilibrium Moisture Content Estimation in Thermally Modified Beech Wood by FT-NIR Spectroscopy

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1208/1/012022 ◽

2021 ◽

Vol 1208 (1) ◽

pp. 012022

Author(s):

Nebojša Todorović

Keyword(s):

Moisture Content ◽

Equilibrium Moisture Content ◽

Cross Section ◽

Near Infrared ◽

Prediction Models ◽

Beech Wood ◽

Nir Spectroscopy ◽

Principal Component ◽

Least Squares Regression ◽

The Cross

Abstract Fourier transform near-infrared (FT-NIR) spectroscopy and partial least squares regression (PLS-R) were tested for the possibility of equilibrium moisture content (EMC) prediction in thermally modified beech wood (Fagus moesiaca C.). The samples were modified for 4h at temperatures of 170, 190 and 210 °C. After thermal modification, the samples were kept in a climatic chamber until EMC was reached. FT-NIR spectra (100 scans and 4 cm-1) were collected on the cross-section and radial surfaces at four points. PLS – R models were developed for four spectral regions: the first overtone, the second overtone, the third overtone and the combination band region. Applied thermal treatment caused a decrease of EMC by 42 % at 170 °C, by 53 % at 190 °C, and by 62 % at 210 °C. Principal component analysis (PCA) indicated that there is a difference both between treatments and between wood surfaces. The results of the spectra taken from the radial surface were, in all models, better than the spectra of the cross-section. Related to chemical changes, the first and second overtone region play an important role in the calibrations. The best prediction models for EMC of thermally modified beech wood were obtained from radial surface spectra in the first (Rp2=0.86, RPD=2.69) and second overtone region (Rp2=0.87, RPD=2.70). The obtain results could contribute to the development of predictive models in monitoring of EMC which could significantly improve the quality of industrial production of thermally modified wood.

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2,6-/1,5-Naphthoquinodimethane bridged porphyrin dimer diradicaloids

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424619500998 ◽

2020 ◽

Vol 24 (01n03) ◽

pp. 220-229 ◽

Cited By ~ 2

Author(s):

Hejian Zhang ◽

Jinseok Kim ◽

Hoa Phan ◽

Tun Seng Herng ◽

Tullimilli Y. Gopalakrishna ◽

...

Keyword(s):

Cross Section ◽

Near Infrared ◽

Energy Gap ◽

Magnetic Measurements ◽

Variable Temperature ◽

Photon Absorption ◽

Singlet Ground State ◽

Triplet Energy ◽

Diradical Character ◽

Cross Section Formula

2,6-Naphthoquinodimethane (2,6-NQDM)- and 1,5-naphthoquinodimethane (1,5-NQDM)-bridged porphyrin dimers, 2,6-P2 and 1,5-P2, were synthesized as relatively stable compounds. Both exhibit open-shell singlet ground state according to variable-temperature (VT) NMR and magnetic measurements, as well as restricted active space spin-flip (RAS-SF) calculations. The 1,5-P2 isomer has a larger diradical character ([Formula: see text], based on the RAS-SF calculations) and smaller singlet-triplet energy gap ([Formula: see text] kcal/mol, based on SQUID measurements) compared to the 2,6-P2 isomer ([Formula: see text], [Formula: see text] kcal/mol). In addition, 2,6-P2 shows intense one-photon absorption (OPA) ([Formula: see text] nm, [Formula: see text] M[Formula: see text] cm[Formula: see text] and a large two-photon absorption (TPA) cross-section ([Formula: see text] GM at 1400 nm) in the near-infrared region, while 1,5-P2 with larger diradical character displays red-shifted but weaker OPA ([Formula: see text] nm, [Formula: see text] M[Formula: see text] cm[Formula: see text] and a smaller TPA cross-section ([Formula: see text] GM at 1600 nm). Both compounds show four reversible redox waves and 1,5-P2 has a smaller electrochemical energy gap (1.06 eV vs.1.16 eV for 2,6-P2). Therefore, the bridge structure has a significant impact on the diradical character, electronic properties, and magnetic behaviors of the obtained porphyrin-based diradicaloids.

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