We experimentally study entangled two-photon absorption in rhodamine 6G as a function of the spatial properties of a high flux of broadband entangled photon pairs. We first demonstrate a key signature dependence of the entangled two-photon absorption rate on the type of entangled pair flux attenuation: linear, when the laser pump power is attenuated, and quadratic, when the pair flux itself experiences linear loss. We then perform a fluorescence-based Z-scan measurement to study the influence of beam waist size on the entangled two-photon absorption process and compare this to classical single- and two-photon absorption processes. We demonstrate that the entangled two-photon absorption shares a beam waist dependence similar to that of classical two-photon absorption. This result presents an additional argument for the wide range of contrasting values of quoted entangled two-photon absorption cross sections of dyes in literature.
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http://dx.doi.org/10.1103/PhysRevLett.129.183601 | DOI Listing |
Analyst
January 2025
Anhui Provincial Key Laboratory of Biomedical Materials and Chemical Measurement, Laboratory of Functionalized Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, P. R. China.
It is highly required to rationally design fluorescent probes a molecular engineering strategy with desired analytical performance for applications in sensing and imaging. Reaction-based fluorescent probes for highly selective sensing of cysteine (Cys) are mainly based on the participation of Cys in reactions such as, addition-cyclization with acrylates, cyclization with aldehydes, coordination displacement, Michael addition reactions, and cleavage reactions. Cys-triggered reactions with the O atoms of ether bonds has also been used to construct reaction-based fluorescent probes based on the substitution of the ether with the nucleophilic thiolate of Cys.
View Article and Find Full Text PDFACS Nano
January 2025
Center for Terahertz Waves and School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China.
The physical picture for photocurrent injection and coherent control in intrinsic graphene under two-color laser excitation remains obscure. Previously, photocurrent injection of intrinsic graphene was attributed to the quantum interference between two electronic transition pathways of single-photon and two-photon absorptions as well as layer-to-layer coupling. Here, we show that quantum interference between stimulated electronic Raman scattering and single-photon absorption plays a very important role in contributing to the total photocurrent, while interlayer coupling does not sufficiently affect the photocurrent injection, which is in contrast to the previous interpretation of the experimental results on photocurrent injection and coherent control.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Physics, K.S.M Devaswom Board College, Sasthamcotta, Kollam, India.
Transition metal based optical limiting materials have garnered significant attention due their crucial role in protecting sensitive optical system from high intense laser damage. Transition metal molybdates exhibits nonlinear optical (NLO) response, which attenuate highly intense light by transmitting light of desired intensity. Herein we report Silver molybdate (AgMoO) nanostructures doped with erbium (Er) ions were successfully synthesized by simple co-precipitation technique.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Max Planck Institute for Medical Research, Jahnstr. 29, Heidelberg 69120, Germany.
Orange carotenoid protein (OCP) is a photoactive protein that mediates photoprotection in cyanobacteria. OCP binds different ketocarotenoid chromophores such as echinenone (ECN), 3'- hydroxyechinenone (hECN), and canthaxanthin (CAN). In the dark, OCP is in an inactive orange form known as OCP; upon illumination, a red active state is formed, referred to as OCP, that can interact with the phycobilisome.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
MOE Laboratory of Bioinorganic and Synthetic Chemistry, Lehn Institute of Functional Materials, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, China.
Immobilizing organic chromophores within the rigid framework of metal-organic frameworks (MOFs) augments fluorescence by effectively curtailing molecular motions. Yet, the substantial interspaces and free volumes inherent to MOFs can undermine photoluminescence efficiency, as they partially constrain intramolecular dynamics. In this study, we achieved optimization of both one- and two-photon excited fluorescence by incorporating linkers into an interpenetrated tetraphenylethene-based MOF (TPE-MOF).
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