A technique for the spatially resolved and molecule-specific detection of chemical vapors is presented. The chemical specificity arises from a transient absorption spectrum where an ultraviolet (UV) pulse excites the molecule to a Rydberg state, and a near-infrared (NIR) or visible probe pulse records a transient absorption spectrum. By recording the NIR pulse reflected off a random, distant object and measuring the elapsed time between the emission of the UV pulse and the absorption of a counter-propagating NIR pulse, the distance to the absorber is obtained. The feasibility of the approach is demonstrated by detecting acetone plumes with millimeter scale spatial resolution.
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http://dx.doi.org/10.1364/OL.43.001279 | DOI Listing |
J Phys Chem Lett
January 2025
School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6012, New Zealand.
The organic semiconductor Y6 has been extensively used as an acceptor in organic photovoltaic devices, yielding high efficiencies. Its unique properties include a high refractive index, intrinsic exciton dissociation, and barrierless charge generation in bulk heterojunctions. However, the direct impact of the crystal packing morphology on the photophysics of Y6 has remained elusive, hindering further development of heterojunction and homojunction devices.
View Article and Find Full Text PDFChem Sci
January 2025
Chemistry and Physics of Materials Unit, School of Advanced Materials (SAMat), Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur Bangalore 560064 India https://www.jncasr.ac.in/faculty/tmaji.
Coordination-driven metallo-supramolecular polymers hold significant potential as highly efficient catalysts for photocatalytic CO reduction, owing to the covalent integration of the light harvesting unit, catalytic center and intrinsic hierarchical nanostructures. In this study, we present the synthesis, characterization, and gelation behaviour of a novel low molecular weight gelator (LMWG) integrating a benzo[1,2-:4,5-']dithiophene core with terpyridine (TPY) units alkyl amide chains (TPY-BDT). The two TPY ends of the TPY-BDT unit efficiently chelate with metal ions, enabling the formation of a metallo-supramolecular polymer that brings together the catalytic center and a photosensitizer in close proximity, maximizing catalytic efficiency for CO reduction.
View Article and Find Full Text PDFF1000Res
January 2025
Departments of Psychiatry, Neurology, Radiology, and Neuroscience, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA.
Reddy and Reddy (2014) discuss the optimal timing for lithium levels in patients taking once-daily extended-release lithium formulations. They argue for blood sampling 24 h after the previous dose rather than the standard 12 h. I interpret the data quite differently.
View Article and Find Full Text PDFThe intrinsic spontaneous and piezoelectric polarizations of GaN lead to the formation of triangular wells and barriers, resulting in the manifestation of chaotic transport models in GaN quantum well intersubband transition (ISBT) infrared detectors and giving rise to various adverse effects. The APSYS software was utilized to construct a novel GaN quantum well ISBT infrared detector in this study. By endeavoring to modify the quantum well structure, our objective was to precisely adjust the energy level of the first excited state (E1) to align with the apex of the triangular barrier.
View Article and Find Full Text PDFWe present the subcycle spectral structures from attosecond transient absorption spectra of helium by accurately solving the full three-dimensional time-dependent Schrödinger equation in extreme ultraviolet attosecond pulse and an orthogonally polarized infrared (IR) laser field. We discover that the subcycle spectral features associated with the dressed 1 ( ≥ 4) states and light-induced states, referred to as , , and , can be strongly modified or even enhanced when the strength ratio of the orthogonal laser field in two polarized laser directions changes. To understand the spectral evolution of the subcycle structures, we perform calculations of the time-dependent population and time-frequency analysis.
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