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We propose a novel all-optical frequency upconversion technique for radio-over-fiber (RoF) systems based on cross-gain modulation (XGM) and cross-polarization modulation (XPolM) in a semiconductor optical amplifier (SOA). A local oscillator signal is carried onto a continuous wave probe beam with orthogonally polarized single-sideband (SSB) modulation using a polarization modulator and a tunable optical filter. The intermediate frequency signal carried by a pump beam is only intensity modulated onto the sideband of the probe beam while the carrier of the probe beam is unmodulated thanks to the joint use of the XGM and XPolM effects in the SOA. This SSB upconversion scheme is inherently free from the chromatic-dispersion-induced power fading after transmission over single-mode fiber. The proposed scheme is theoretically analyzed and experimentally verified.
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http://dx.doi.org/10.1364/OL.39.002672 | DOI Listing |
Phys Rev Lett
August 2025
Università degli Studi di Padova, Dipartimento di Fisica e Astronomia, Via Marzolo 8, 35131 Padova, Italy.
Feebly interacting particles, such as sterile neutrinos, dark photons, and axions, can be abundantly produced in the proto-neutron star (PNS) formed in core-collapse supernovae (CCSNe). These particles can decay into photons or charged leptons, depositing energy outside the PNS. Strong bounds on new particles can thus be derived from the observed luminosity of CCSNe, with even tighter bounds obtained from low-energy SNe observations.
View Article and Find Full Text PDFAdv Mater
September 2025
Dept. of Physics, Pennsylvania State University, University Park, PA, 16802, USA.
Altermagnets are a newly identified family of collinear antiferromagnets with a momentum-dependent spin-split band structure of non-relativistic origin, derived from spin-group symmetry-protected crystal structures. Among candidate altermagnets, CrSb is attractive for potential applications because of a large spin-splitting near the Fermi level and a high Néel transition temperature of around 700 K. Molecular beam epitaxy is used to synthesize CrSb (0001) thin films with thicknesses ranging from 10 to 100 nm.
View Article and Find Full Text PDFJ Phys Chem Lett
September 2025
Université Paris-Saclay, CEA Saclay, CNRS, NIMBE, UMR 3685, LIONS, 91191 Gif-Sur-Yvette CEDEX, France.
The effect of adding Na and Mg metal ions on soft X-ray induced photochemistry (SXIP) is investigated. To that aim, the soft X-ray beam of the METROLOGIE beamline at the SOLEIL synchrotron was extracted through air to irradiate solutions circulating in a microfluidic cell. Benzoate was used as a sensitive profluorescent probe for hydroxyl radicals.
View Article and Find Full Text PDFRev Sci Instrum
September 2025
Department of Physics, Rikkyo University, 171-8501 Tokyo, Japan.
The use of a wire probe is a robust method for beam profile measurement, but it can only provide a 1D projection of the beam profile. In this study, we developed a novel method for measuring a beam projected from a 360° angle by a dual-axis rotation of a wire and obtaining a complete 2D profile via image reconstruction. We conducted a proof-of-principle study using an Ar+ ion beam and optimized the reconstruction algorithm.
View Article and Find Full Text PDFAnal Methods
September 2025
Vrije Universiteit Amsterdam, Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Division of BioAnalytical Chemistry, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
Polymer-based nanoparticles (PNPs) find wide application in material and pharmaceutical sciences. In order to determine the quality of produced PNPs and understand their function, analytical characterization is essential. Recently, two-dimensional liquid chromatography (2D-LC) has been introduced as an effective means to probe multiple PNP properties, such as size and composition, in an integrated manner.
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