We demonstrate tunable spectral enhancement of the supercontinuum generated in a microstructured fiber with a fiber long-period grating. The long-period grating leads to phase distortion and loss that, with subsequent high-intensity propagation in uniform fiber, evolves into an enhancement around the grating's resonant wavelengths. Wavelength tunability is achieved by varying the temperature or the ambient refractive index, and the spectral peak can be extinguished by immersing the grating in index-matching oil.
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http://dx.doi.org/10.1364/ol.32.001644 | DOI Listing |
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December 2024
School of Microelectronics, Northwestern Polytechnical University, 127 West Youyi Road, Beilin District, Xi'an, Shaanxi, 710072, P. R. China.
2D photodetectors operating in photovoltaic mode exhibit a trade-off between response speed and photoresponsivity. This work presents a phototransistor based on SnS/ReSe heterojunction. Under negative bias, the energy band spike at the heterojunction interface impedes the carrier drifting so that the dark current is as low as 10 A.
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December 2024
School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China.
Background noise interferes with the accurate detection of early tumor biomarkers. This study introduces a method that effectively reduces background noise to enhance detection accuracy by combining a color-coded signaling approach with the unique fluorescent properties and room-temperature tunable quantum spin characteristics of fluorescent diamonds (FNDs) with nitrogen-vacancy centers. In this approach, a red signal indicates the presence of the target analyte within the spectral region, a green signal indicates its absence, and a yellow signal indicates the need for further analysis using FNDs' quantum spin properties for optical detection magnetic resonance (ODMR) to distinguish the FND signal from background noise.
View Article and Find Full Text PDFAnal Chem
December 2024
Joint Mass Spectrometry Centre/Chair of Analytical Chemistry, University of Rostock, 18059 Rostock, Germany.
To our knowledge, this study presents the first implementation of wavelength-resolved resonance-enhanced multiphoton ionization (REMPI) spectroscopy under atmospheric pressure ionization conditions using a high-resolution mass spectrometric system. Atmospheric pressure laser ionization MS spectroscopic measurements were conducted on over 70 different polycyclic aromatic hydrocarbons (PAHs) and hetero-PAHs (N, S, and O) in standard solutions, as well as three complex PAH-containing samples. The results demonstrate the successful transfer of REMPI spectroscopy from vacuum to atmospheric pressure conditions, maintaining spectral integrity without significant band broadening.
View Article and Find Full Text PDFAdv Mater
December 2024
Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 3, Groningen, 9747 AG, The Netherlands.
In recent years, metal halide perovskite-based light-emitting diodes (LEDs) have garnered significant attention as they display high quantum efficiency, good spectral tunability, and are expected to have low processing costs. When the peak emission wavelength is beyond 900 nm the interest is even higher because of the critical importance of this wavelength for biomedical imaging, night vision, and sensing. However, many challenges persist in fabricating these high-performance NIR LEDs, particularly for wavelengths above 950 nm, which appear to be limited by low radiance and poor stability.
View Article and Find Full Text PDFSci Data
December 2024
Key Laboratory of Photoelectronic Imaging Technology and System of Ministry of Education of China, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China.
Polarization multispectral imaging has advanced significantly due to its robust information representation capability. Imaging application requires rigorous simulation evaluation and experimental validation using standardized datasets. However, the current full-Stokes polarization multispectral images (FSPMI) dataset, while providing simulation data, is limited by image drift and spectral bands.
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