Thanks to a portable dual-frequency Brillouin fiber laser and a 1.55 μm photomixer, we report the generation of a highly coherent kilohertz level submillimeter wave emission. Low-cost telecommunications components are used to achieve very simple source architecture. The photomixer is composed of a unitravelling carrier photodiode integrated with an antenna. An emission at 316 GHz is observed and analyzed thanks to heterodyne detection with a signal-to-noise ratio >65 dB and a ~1 kHz linewidth. The phase noise of the proposed source has the same performance at 1.7 and 316 GHz. We show that this source has comparable or better phase noise compared to electrical oscillators and the tunability is much wider.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OL.36.002044 | DOI Listing |
Brain Sci
December 2024
Department of Speech, Hearing and Phonetic Sciences, Division of Psychology and Language Sciences, University College London, Chandler House 2 Wakefield Street, London WC1N 1PF, UK.
Speech is a highly skilled motor activity that shares a core problem with other motor skills: how to reduce the massive degrees of freedom (DOF) to the extent that the central nervous control and learning of complex motor movements become possible. It is hypothesized in this paper that a key solution to the DOF problem is to eliminate most of the temporal degrees of freedom by synchronizing concurrent movements, and that this is performed in speech through the syllable-a mechanism that synchronizes consonantal, vocalic, and laryngeal gestures. Under this hypothesis, syllable articulation is enabled by three basic mechanisms: target approximation, edge-synchronization, and tactile anchoring.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Experimental Physics V, Department of Physics, University of Bayreuth, D-95447 Bayreuth, Germany.
Photosynthetic microbes have evolved and successfully adapted to the ever-changing environmental conditions in complex microhabitats throughout almost all ecosystems on Earth. In the absence of light, they can sustain their biological functionalities through aerobic respiration, and even in anoxic conditions through anaerobic metabolic activity. For a suspension of photosynthetic microbes in an anaerobic environment, individual cellular motility is directly controlled by its photosynthetic activity, i.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
DICP: Chinese Academy of Sciences Dalian Institute of Chemical Physics, State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, CHINA.
Broad-temperature optical thermometry necessitates materials with exceptional sensitivity and stability across varied thermal conditions, presenting challenges for conventional systems. Here, we report a lead-free, vacancy-ordered perovskite Cs2TeCl6, that achieves precise temperature sensing through a novel combination of self-trapped excitons (STEs) photoluminescence (PL) lifetime modulation and unprecedented fifth-order phonon anharmonicity. The STEs PL lifetime demonstrates a highly temperature-sensitive response from 200 to 300 K, ideal for low-to-intermediate thermal sensing.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Laboratory of Structural and Functional Organization of Chromosomes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia.
Dictyostelium discoideum is a unicellular slime mold, developing into a multicellular fruiting body upon starvation. Development is accompanied by large-scale shifts in gene expression program, but underlying features of chromatin spatial organization remain unknown. Here, we report that the Dictyostelium 3D genome is organized into positionally conserved, largely consecutive, non-hierarchical and weakly insulated loops at the onset of multicellular development.
View Article and Find Full Text PDFOphthalmology
January 2025
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510623, China. Electronic address:
Purpose: To describe the longitudinal changes in peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell-inner plexiform layer (mGC-IPL) thicknesses in highly myopic eyes with and without glaucoma, and to investigate the effects of high myopia (HM) on the sectoral patterns of pRNFL and mGC-IPL thinning.
Design: Longitudinal cohort study.
Participants: A total of 243 eyes from 243 individuals with 3-year follow-up were included in this study: 109 eyes in the HM group, 64 eyes in the open-angle glaucoma (OAG) group and 70 eyes in the highly myopic glaucoma (HMG) group.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!