The operation of the bridge mutually pumped phase conjugator is reported in a planar waveguide structure in photorefractive BaTiO(3). The waveguide was fabricated by the technique of ion implantation, using 1.5-MeVH(+) ions at a dose of 10(16) ions/cm(2). An order of magnitude decrease in response time is observed in the waveguide as compared with typical values obtained in bulk crystals, probably as a result of a combination of the optical confinement within the waveguide and possible modification of the charge-transport properties induced by the implantation process.
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http://dx.doi.org/10.1364/AO.32.005299 | DOI Listing |
ACS Nano
November 2024
Department of Physics, University of Hong Kong, Hong Kong SAR 999077, China.
Excitons in two-dimensional (2D) semiconductors are particularly exciting, as reduced screening and dimensional confinement foster their pronounced many-body interactions. Optical pumping is typically used to create excitons so as to study their properties, but at the same time such pumping can also create unbound charge carriers. This makes experimental determination of the exciton-exciton interactions difficult.
View Article and Find Full Text PDFPLoS One
October 2024
Department of Biological Sciences, Bose Institute, Kolkata, India.
Trans-Himalayan hot spring waters rich in boron, chlorine, sodium and sulfur (but poor in calcium and silicon) are known based on PCR-amplified 16S rRNA gene sequence data to harbor high diversities of infiltrating bacterial mesophiles. Yet, little is known about the community structure and functions, primary productivity, mutual interactions, and thermal adaptations of the microorganisms present in the steaming waters discharged by these geochemically peculiar spring systems. We revealed these aspects of a bacteria-dominated microbiome (microbial cell density ~8.
View Article and Find Full Text PDFJ Neurosci
November 2024
Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
Humans possess a remarkable ability to rapidly access diverse information from others' faces with just a brief glance, which is crucial for intricate social interactions. While previous studies using event-related potentials/fields have explored various face dimensions during this process, the interplay between these dimensions remains unclear. Here, by applying multivariate decoding analysis to neural signals recorded with optically pumped magnetometer magnetoencephalography, we systematically investigated the temporal interactions between invariant and variable aspects of face stimuli, including race, gender, age, and expression.
View Article and Find Full Text PDFBioengineering (Basel)
June 2024
Key Laboratory of Ultra-Weak Magnetic Field Measurement Technology, Ministry of Education, School of Instrumentation and Optoelectronic Engineering, Beihang University, 37 Xueyuan Rd., Haidian Dist., Beijing 100083, China.
Multivariate pattern analysis (MVPA) has played an extensive role in interpreting brain activity, which has been applied in studies with modalities such as functional Magnetic Resonance Imaging (fMRI), Magnetoencephalography (MEG) and Electroencephalography (EEG). The advent of wearable MEG systems based on optically pumped magnetometers (OPMs), i.e.
View Article and Find Full Text PDFNeuroimage
August 2024
School of Instrumentation Science and Optoelectronic Engineering, Beihang University, Beijing 100191, China; Key Laboratory of Ultra-Weak Magnetic Field Measurement Technology, Ministry of Education, School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing 100191, China; National Innovation Platform for industry-Education Integration in Medicine-Engineering Interdisciplinary, Shandong Key Laboratory for Magnetic Field-free Medicine and Functional Imaging, Shandong University, Research Institute of Shandong University, Jinan, 250014, China; National Institute of Extremely-Weak Magnetic Field Infrastructure, Hangzhou 310051, China. Electronic address:
Optically pumped magnetometer magnetoencephalography (OPM-MEG) holds significant promise for clinical functional brain imaging due to its superior spatiotemporal resolution. However, effectively suppressing metallic artifacts, particularly from devices such as orthodontic braces and vagal nerve stimulators remains a major challenge, hindering the wider clinical application of wearable OPM-MEG devices. A comprehensive analysis of metal artifact characteristics from time, frequency, and time-frequency perspectives was conducted for the first time using an OPM-MEG device in clinical medicine.
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