- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Handbook of Exoplanets || SPIRou: A NIR Spectropolarimeter/High-Precision Velocimeter for the CFHT
摘要： SPIRou is a near-infrared (nIR) spectropolarimeter/velocimeter for the Canada-France-Hawaii Telescope (CFHT) that will focus on two forefront science topics, (i) the quest for habitable Earthlike planets around nearby M stars and (ii) the study of low-mass star/planet formation in the presence of magnetic fields. SPIRou will also efficiently tackle many key programs beyond these two main goals, from weather patterns on brown dwarfs to solar system planet and exoplanet atmospheres. SPIRou will cover a wide spectral domain in a single exposure (0.98–2.44 μm) at a resolving power of 70 K, yielding unpolarized and polarized spectra of low-mass stars with a 15% average throughput at a radial velocity (RV) precision of 1 m s?1. It consists of a Cassegrain unit mounted at the Cassegrain focus of CFHT and featuring an achromatic polarimeter, coupled to a cryogenic spectrograph cooled down at 80 K through a fluoride fiber link. SPIRou is currently integrated at IRAP/OMP and will be mounted at CFHT in 2018 Q1 for a first light scheduled in early 2018. Science operation is predicted to begin in 2018 S2, allowing many fruitful synergies with major ground and space instruments such as the JWST, TESS, ALMA, and later-on PLATO and the ELT.
关键词： velocimeter,CFHT,exoplanets,star formation,SPIRou,magnetic fields,near-infrared,spectropolarimeter
更新于2025-09-23 15:21:01
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Ultrafast energy absorption and photoexcitation of bulk plasmon in crystalline silicon subjected to intense near-infrared ultrashort laser pulses
摘要： We investigate the non-linear response and energy absorption in bulk silicon irradiated by intense 12-fs near-infrared laser pulses. Depending on the laser intensity, we distinguish two regimes of non-linear absorption of the laser energy: for low intensities, energy deposition and photoionization involve perturbative three-photon transition through the direct bandgap of silicon. For laser intensities near and above 1014 W/cm2, corresponding to photocarrier density of order 1022 cm?3, we find that absorption at near-infrared wavelengths is greatly enhanced due to excitation of bulk plasmon resonance. In this regime, the energy transfer to electrons exceeds a few times the thermal melting threshold of Si. The optical reflectivity of the photoexcited solid is found in good qualitative agreement with existing experimental data. In particular, the model predicts that the main features of the reflectivity curve of photoexcited Si as a function of the laser fluence are determined by the competition between state and band filling associated with Pauli exclusion principle and Drude free-carrier response. The non-linear response of the photoexcited solid is also investigated for irradiation of silicon with a sequence of two strong and temporary non-overlapping pulses. The cumulative effect of the two pulses is non-additive in terms of deposited energy. Photoionization and energy absorption on the leading edge of the second pulse is greatly enhanced due to free carrier absorption.
关键词： bulk silicon,optical reflectivity,photoexcited solid,near-infrared laser pulses,Drude free-carrier response,non-linear response,energy absorption,plasmon resonance
更新于2025-09-23 15:21:01
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Boosting Perovskite Photodetector Performance in NIR Using Plasmonic Bowtie Nanoantenna Arrays
摘要： Triple-cation mixed metal halide perovskites are important optoelectronic materials due to their high photon to electron conversion efficiency, low exciton binding energy, and good thermal stability. However, the perovskites have low photon to electron conversion efficiency in near-infrared (NIR) due to their weak intrinsic absorption at longer wavelength, especially near the band edge and over the bandgap wavelength. A plasmonic functionalized perovskite photodetector (PD) is designed and fabricated in this study, in which the perovskite ((Cs0.06FA0.79MA0.15)Pb(I0.85Br0.15)3) active materials are spin-coated on the surface of Au bowtie nanoantenna (BNA) arrays substrate. Under 785 nm laser illumination, near the bandedge of perovskite, the fabricated BNA-based plasmonic PD exhibits ≈2962% enhancement in the photoresponse over the Si/SiO2-based normal PD. Moreover, the detectivity of the plasmonic PD has a value of 1.5 × 1012 with external quantum efficiency as high as 188.8%, more than 30 times over the normal PD. The strong boosting in the plasmonic PD performance is attributed to the enhanced electric field around BNA arrays through the coupling of localized surface plasmon resonance. The demonstrated BNA-perovskite design can also be used to enhance performance of other optoelectronic devices, and the concept can be extended to other spectral regions with different active materials.
关键词： near infrared,bowtie nanoantenna arrays,perovskite photodetectors,localized surface plasmon resonance
更新于2025-09-23 15:21:01
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850 nm Pure Near-Infrared Emitting Iridium Complex for Solution-processed Organic Light-Emitting Diodes
摘要： High-performance pure near-infrared organic light-emitting materials and devices with full emission over 700 nm are still rare, though urgently needed. Iridium(III) complexes have been proven to be an important class of NIR emitters. Herein, we report a new NIR homoleptic Ir(III) complex, tris[1,4-di(5-n-octylthiophen-2-yl)benzo[g]phthalazine] iridium(III) (Ir(dotbpa)3), with full emission beyond 700 nm and Iridium mass content as low as 10 wt%. Thanks to the introduction of flexible n-octyl groups, Ir(dotbpa)3 shows greatly improved solubility and excellent solution-processability in comparison with its counterpart Ir(dtbpa)3. By employing a multifunctional host, solution-processed NIR-OLEDs were fabricated with a simple structure of only three organic layers and demonstrated pure NIR emission starting from 725 nm and peaking at 850 nm with maximum external quantum efficiency of 0.17%, which is the first example to achieve pure NIR-OLEDs based on Ir(III) emitters.
关键词： Pure NIR emission,Near-infrared,Solution-processed,Iridium(III) complex,Organic light-emitting diodes
更新于2025-09-23 15:21:01
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NIR Infrared imaging after peritumoral injection of indocyanine green to guide lymph node dissection in head and neck squamous cell carcinoma: A pilot feasibility study
摘要： In head and neck squamous cell carcinoma (HNSCC), neck dissection is part of the surgical therapy. Beyond to the fact that radicality is a critical prognostic factor, this dissection could lead to significant morbidity, potentially avoidable when resected lymph nodes (LN) are proven to be non-invaded at pathology. Therefore, the definition of a method able to reliably identify the specific LN drainage area in HNSCC would represent a relevant progress, to better guide the neck dissection, potentially improving the radicality and reducing the morbidity. As near-infrared fluorescence imaging (NIR-FI) after indocyanine green (ICG) peritumoral injection has been validated as a sentinel procedure, we hypothesized that this approach could represent a new technique to identify the tumor-drainage area in HNSCC. We prospectively evaluated this technique in 14 patients with oral or oropharyngeal carcinoma scheduled for primary tumor resection and LN dissection. The trial was approved by the ethics committee of the Institut Jules Bordet (CE-2178) (EudraCT 2014-000298-37) and all patients signed informed consent before inclusion.
关键词： Head and neck squamous cell carcinoma,Indocyanine green,Near-infrared fluorescence imaging,Lymph node dissection,Surgical guidance
更新于2025-09-23 15:21:01
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Construction of global and robust near-infrared calibration models based on hybrid calibration sets using Partial Least Squares (PLS) regression
摘要： Near-infrared spectroscopy (NIR) models built on a particular instrument are often invalid on other instruments due to spectral inconsistencies between the instruments. In the present work, global and robust NIR calibration models were constructed by partial least square (PLS) regression based on hybrid calibration sets, which are composed of both primary and secondary spectra. Three datasets were used as case studies. The first consisted of 72 radix scutellaria samples measured on two NIR spectrometers with known baicalin content. The second was composed of 80 corn samples measured on two instruments with known moisture, oil, and protein concentrations. The third dataset included 279 primary samples of tobacco with known nicotine content and 78 secondary samples of tobacco with known nicotine concentrations. The effect of the number of secondary spectra in the hybrid calibration sets and the methods for selecting secondary spectra on the PLS model performance were investigated by comparing the results obtained from different calibration sets. This study shows that the global and robust calibration models accurately predicted both primary and secondary samples as long as the ratios of the number of primary spectra to the number of secondary spectra were less than 22. The models performance was not influenced by the selection method of the secondary spectra. The hybrid calibration sets included the primary spectral information and also the secondary spectra; rendering the constructed global and robust models applicable to both primary and secondary instruments.
关键词： global and robust models,hybrid calibration set,Near-infrared spectroscopy,partial least squares (PLS) regression
更新于2025-09-23 15:21:01
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Defects Type Dependent Near-Infrared-Driven Photocatalytic Bacterial Inactivation by Defective Bi2S3 nanorods
摘要： Defects engineering is crucial in tailoring the photocatalytic efficiency, but it suffers from uncertainty to determine the vacancy type, and it is confusing which type of the vacancy can better promote the photocatalytic efficiency. In this study, Bi2S3 nanorods with bismuth or sulfur vacancies were synthesized respectively to investigate their distinct effects on the electronic structure, electron-hole separation characteristics and near-infrared (NIR)-driven photocatalytic bacterial inactivation activity. Both bismuth and sulfur vacancies can enhance the light absorption ability of Bi2S3. However, the life span of photoinduced electrons is extended by bismuth vacancy but shortened by sulfur vacancy. Due to these advantages, the bismuth vacant Bi2S3 can fully inactivated 7 log E. coli cells within 40 min of NIR irradiation, displaying a better NIR-driven photocatalytic bacterial inactivation efficiency than that of Bi2S3 with sulfur vacancy. This study disclosed the defects type dependent photocatalytic behaviors, providing new insights into designing highly efficient photocatalyst.
关键词： defect type dependent efficiency,near-infrared-driven photocatalysts,defective Bi2S3 nanorods
更新于2025-09-23 15:21:01
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A dual colorimetric and near-infrared fluorescent turn-on probe for Hg2+ detection and its applications
摘要： The increasing Hg2+ contamination in environment and ecosystem has gained wide attention and thus demands for its facile and effective detection. In this study, we constructed a new fluorescent probe (E)-2-(2-(3-(1,3-dithian-2-yl)-4-hydroxystyryl)-4H-chromen-4-ylidene)malononitrile (DCM-Hg) for Hg2+ detection by incorporating the 1, 3-dithiane group to the dicyanomethylene-4H-pyran fluorophore for the first time. This probe can selectively detect Hg2+ via the Hg2+-triggered deprotection reaction of thioacetals, which leads to a distinct color change from purple to pink and obvious fluorescence enhancement in the near-infrared (NIR) region. The NIR fluorescence intensity increased linearly with Hg2+ level within the range from 0 to 100 μM and the detection limit of DCM-Hg for Hg2+ was found to be 6.8 × 10-8 mol/L. Moreover, the probe could sense Hg2+ on paper strips and image Hg2+ in living cells with low cytotoxicity, which demonstrates its potential application in environment and biological science.
关键词： Selectivity,Near-infrared,Imaging,Color change,Hg2+
更新于2025-09-23 15:21:01
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Dynamically tunable perfect absorption based on the phase transition of vanadium dioxide with aluminum hole arrays
摘要： Integrating plasmonic nanostructures with functional materials can further control over the optical resonant responses. A perfect absorber (PA) consisting of aluminum (Al) ring array intercalated with vanadium dioxide (VO2) disk is presented. The resonance wavelength of absorption peak can be tuned over a wide range in the visible (Vis) and near-infrared (NIR) regimes. The absorption peak shifts from 770 nm to 1336 nm while VO2 undergoes a structural transition from metallic phase (m-VO2) to insulator phase (i-VO2), resulting in a relative 73.5% wavelength shift. In addition, the absorption peak is strongly dependent on the height and radius of the ring disk as well as the period of lattice. Our work also suggests that the designed VO2-based absorber has the potential to overcome the di?culty in performing dynamically tunable resonances and near-unity absorbance with wide angle of incidence as well as weak polarization dependence.
关键词： Vanadium dioxide (VO2),Visible and near-infrared spectral,Phase change material,Perfect absorption
更新于2025-09-23 15:21:01
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SSC prediction of cherry tomatoes based on IRIV-CS-SVR model and near infrared reflectance spectroscopy
摘要： As one of the most important indexes of internal quality testing of fruit, soluble solids content (SSC) is significant for its rapid and efficient nondestructive testing by using near infrared reflectance spectroscopy (NIRS). In this article, 126 cherry tomatoes were selected as the research object. Reflectance spectra data of 228 bands in cherry tomatoes were acquired by the near infrared spectrometer and SSC was measured by the hand-held refractometer. Savitzky–Golay (SG) combined with multiplicative scatter correction (MSC) was used to preprocess the spectral data to reduce the effects of light scattering and other noise. Then, the dimensions of spectral data were reduced by iteratively retaining informative variables (IRIV) algorithm and 10 characteristic wavelengths were obtained, which were 1,080.37, 1,113.62, 1,117.3, 1,297.57, 1,301.02, 1,538.32, 1,540.40, 1,590.72, 1,615.94, and 1,636.89 nm, respectively. Subsequently, support vector regression (SVR) and its two optimization models, PSO-SVR and CS-SVR, were respectively used to establish SSC prediction models based on full spectra and characteristic spectra. The experimental results showed the IRIV-CS-SVR model for SSC prediction achieved the accuracy with R2 C of 0.9845. Thus, it is feasible to use NIRS with IRIV-CS-SVR to make a rapid and efficient nondestructive SSC prediction of cherry tomatoes.
关键词： IRIV-CS-SVR model,SSC prediction,cherry tomatoes,near infrared reflectance spectroscopy
更新于2025-09-23 15:21:01