The origin of second harmonic generation (SHG) signal in otoconia was investigated. SHG signal intensity from otoconia was compared to pure calcite crystals, given calcite is the primary component of otoconia and is known to emit surface SHG. The SHG intensity from calcite was found to be ∼41× weaker than the SHG intensity from otoconia signifying that the SHG signal from otoconia is likely generated from the organic matrix. Furthermore, the SHG intensity from otoconia increased when treated with a chelating agent known to dissolve calcite which confirms that calcite is not the source of SHG. Additionally, polarization-resolved SHG microscopy imaging revealed that the arrangement of the SHG emitters is radial and can form highly ordered domains.
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http://dx.doi.org/10.1364/BOE.457967 | DOI Listing |
Lithium niobate (LiNbO) has shown great potential for applications in nonlinear metasurfaces, thanks to its large second-order nonlinear coefficients and high integration capabilities. Optical resonances play a crucial role in further enhancing the nonlinear optical responses of LiNbO metasurfaces (LNMS). In this study, both numerically and experimentally, we designed and fabricated a metasurface structure that supports toroidal dipole (TD) resonance to enhance second-harmonic generation (SHG).
View Article and Find Full Text PDFEur Biophys J
January 2025
Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
Compared to fluorescence, second harmonic generation (SHG) has recently emerged as an excellent signal for imaging probes due to its unmatched advantages in terms of no photobleaching, no phototoxicity, no signal saturation, as well as the superior imaging accuracy with excellent avoidance of background noise. Existing SHG probes are constructed from heavy metals and are cellular exogenous, presenting with high cytotoxicity, difficult cellular uptake, and the limitation of non-heritability. We, therefore, initially propose an innovative gene-encoded bioprotein SHG probe derived from Autographa californica nuclear polyhedrosis virus (AcMNPV) polyhedrin.
View Article and Find Full Text PDFDalton Trans
January 2025
School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, 330031, People's Republic of China.
Three-component crown ether phase change materials are characterized by a structural phase change in response to external stimuli such as temperature and electric or magnetic fields, resulting in significant changes in physical properties. In this work, we designed and synthesized two novel host-guest crown ether molecules [(PTFMA)(15-crown-5)ClO] (1) and [(PTFMA)(15-crown-5)PF] (2), through the reaction of -trifluoromethylaniline (PTFMA) with 15-crown-5 in perchloric acid or hexafluorophosphoric acid aqueous solution. Compound 1 undergoes a structural change from the non-centrosymmetric space group (2) to the centrosymmetric space group (2/) with increasing temperature.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
National Research Council-National Institute of Optics, Largo E. Fermi, 6, 50125 Florence, Italy.
Understanding the deterioration processes in wooden artefacts is essential for accurately assessing their conservation status and developing effective preservation strategies. Advanced imaging techniques are currently being explored to study the impact of chemical changes on the structural and mechanical properties of wood. Nonlinear optical modalities, including second harmonic generation (SHG) and two-photon excited fluorescence (TPEF), combined with fluorescence lifetime imaging microscopy (FLIM), offer a promising non-destructive diagnostic method for evaluating lignocellulose-based materials.
View Article and Find Full Text PDFACS Omega
December 2024
Institut für Theoretische Physik and Center for Materials Research (LaMa), Justus-Liebig-Universität Gießen, 35392 Gießen, Germany.
The second harmonic generation (SHG) properties of adamantane-based tetraphenyl clusters are predicted from first principles and analyzed on the basis of the involved electronic transitions. In particular, the effect of a tetrel substitution in the cluster core on the nonlinear optical response is investigated. Electronic transitions spatially localized at the substituents are found to be responsible for the optical nonlinearities.
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