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Yb-doped fluoride has been demonstrated to be potential crystals for application in efficient ultrafast lasers. However, the trade-off between the shorter pulses with higher efficiencies is a challenge. In this work, using , : crystal, we report on a sub-50-fs Kerr-lens mode-locked oscillator with an optical efficiency up to 44%. Pumped by a 976-nm diffraction-limited fiber laser and using chirped mirrors combined with prism pairs for the dispersion compensation, a pulse as short as 46 fs was obtained with 620-mW output power, corresponding to an optical efficiency more than 40%. Stable Kerr-lens mode-locking with RMS of output power lower than 0.3% and beam quality factors <1.14 were achieved. Moreover, a maximum output power of 780 mW was obtained in continuous-wave operation with 55.3% optical efficiency. To the best of our knowledge, the results in this work represent the shortest pulses generated from Yb-doped fluoride lasers as well as the highest optical efficiencies ever reported in sub-100 fs Yb bulk lasers.
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http://dx.doi.org/10.1364/AO.509994 | DOI Listing |
Langmuir
September 2025
Microelectronics & Nanotechnology-Shamsuddin Research Centre (MiNT-SRC), Universiti Tun Hussein Onn Malaysia, Batu Pahat 86400 Johor, Malaysia.
Achieving a crack-free, high-surface-area photoanode is essential for maximizing the efficiency of dye-sensitized solar cells (DSSCs). In this work, rutile titanium dioxide (rTiO) nanoflowers were synthesized hydrothermally and then conformally coated with copper(I) oxide (CuO) by RF magnetron sputtering to seal pre-existing cracks and to create a nanothorn surface favorable for dye adsorption. Systematic control of the sputtering time identified 60 min as optimal condition, yielding a photoanode thickness of about 6.
View Article and Find Full Text PDFNanoscale Horiz
September 2025
Theoretical Chemical Physics Group, Research Institute for Materials Science and Engineering, University of Mons, 20 Place du Parc, Mons B-7000, Belgium.
Two-photon spontaneous emission (TPSE) is a second-order quantum process with promising applications in quantum optics that remains largely unexplored in molecular systems, which are usually very inefficient emitters. In this work, we model the first molecular two-photon emitters and establish the design rules, highlighting their differences from those governing two-photon absorbers. Using both time-dependent density functional theory and Pariser-Parr-Pople calculations, we calculate TPSE in three π-conjugated molecules and identify a dominant pathway.
View Article and Find Full Text PDFNanoscale
September 2025
College of Physics, Hebei Normal University, Shijiazhuang 050024, China.
MoSe nanosheet/Si heterojunction photodetectors were fabricated by a mechanical exfoliation method, and their electrical and optical properties at different temperatures were investigated. It was found that the MoSe nanosheet/Si heterojunction device exhibited excellent rectification characteristics at room temperature, and the rectification ratio gradually decreased with the decrease of temperature. The temperature-dependent electrical properties of the MoSe/Si heterojunction device were actually caused by the inhomogeneity of the potential barrier.
View Article and Find Full Text PDFJ Mater Chem B
September 2025
Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
Perylene diimide (PDI) radical anions have attracted increasing attention as hypoxia-responsive photothermal agents due to their strong near-infrared (NIR) absorption and efficient photothermal conversion. However, their biomedical application is often limited by aggregation-induced quenching and poor structural tunability. In this work, we report a rationally engineered four-arm PDI derivative (PDI-4Alky·4Cl) bearing terminal alkyne groups, which not only suppresses π-π stacking steric and electrostatic repulsion, but also serves as a versatile molecular scaffold for further functionalization.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, P. R. China.
Exhaled breath analysis offers noninvasive, early lung cancer detection via volatile organic compound (VOC) biomarkers, surpassing blood-based methods. Surface-enhanced Raman spectroscopy (SERS) is ideal for this purpose, combining molecular fingerprint specificity with single-molecule sensitivity. However, conventional SERS substrates face a fundamental limitation: while porous materials such as metal-organic frameworks effectively adsorb VOCs through their subnanometer pores (0.
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