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It is of great difficulty to obtain deep-UV transparent materials with enhanced second harmonic generation (SHG), mainly limited by the theoretically poor transparency of these materials in the deep-UV spectral region. Here we report a new noncentrosymmetric, deep-UV transparent phosphate RbNaMgPO, which undergoes a thermo-induced reversible phase transition (at a high temperature of 723 K) and correspondingly an evident SHG enhancement up to ∼1.5 times. The phase transition is aroused by the twist of [PO] dimers with deviation from the P-O-P equilibrium positions. Theoretical analyses reveal that the enhanced SHG can be ascribed to the thermo-induced collective alignment of SHG-active [PO] dimers along the polar axis of high-temperature phase. This work provides an unprecedented physical routine (to SHG-enhanced materials) that is distinguished from the traditional one by chemical design and synthesis.
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http://dx.doi.org/10.1021/jacs.7b12518 | DOI Listing |
Light Sci Appl
September 2025
Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Tianjin, China.
Photon upconversion through high harmonic generation, multiphoton absorption, Auger recombination and phonon scattering performs a vital role in energy conversion and renormalization. Considering the reduced dielectric screening and enhanced Coulomb interactions, semiconductor monolayers provide a promising platform to explore photon upconversion at room temperature. Additionally, two-photon upconversion was recently demonstrated as an emerging technique to probe the excitonic dark states due to the extraordinary selection rule compared with conventional excitation.
View Article and Find Full Text PDFLight Sci Appl
September 2025
National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, College of Engineering and Applied Sciences, Nanjing University, 210023, Nanjing, China.
Planar optical elements incorporating space-varying Pancharatnam-Berry phase have revolutionized the manipulation of light fields by enabling continuous control over amplitude, phase, and polarization. While previous research focusing on linear functionalities using apolar liquid crystals (LCs) has attracted much attention, extending this concept to the nonlinear regime offers unprecedented opportunities for advanced optical processing. Here, we demonstrate the reconfigurable nonlinear Pancharatnam-Berry LC diffractive optics in photopatterned ion-doped ferroelectric nematics.
View Article and Find Full Text PDFJ Acoust Soc Am
September 2025
Department of Head and Neck Surgery, University of California, Los Angeles, 31-24 Rehab Center, 1000 Veteran Avenue, Los Angeles, California 90095-1794, USA.
The goal of this study was to understand the interaction between the voice source spectral shape, formant tuning, and fundamental frequency in determining the vocal tract contribution to vocal intensity. Computational voice simulations were performed with parametric variations in both vocal fold and vocal tract configurations. The vocal tract contribution to vocal intensity was quantified as the difference in the A-weighted sound pressure level between the radiated sound pressure and the sound pressure at the glottis.
View Article and Find Full Text PDFChem Sci
September 2025
State Key Laboratory of Crystal Materials, Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, Tianjin University of Technology Tianjin 300384 China
Nonlinear optical (NLO) crystals capable of expanding the spectral region of solid-state are of great importance for many high-tech applications, yet their rational structure design remains a great challenge because of the conflicting property requirements among second harmonic generation (SHG) response, ultraviolet (UV) cut-off edge, and birefringence. Herein, based on the chemical disubstitution of the classic NLO crystal SrBeBO (SBBO), , substituting [BO] triangles with larger π-conjugated [BO] groups and substituting high-toxic [BeO] tetrahedra with environment-friendly [AlO] tetrahedra, a new high-performance aluminoborate NLO crystal, BaAlBO, has been successfully designed and synthesized. The theoretical calculations and optical property measurements indicate that BaAlBO exhibits not only the largest SHG response among the reported aluminoborates (2.
View Article and Find Full Text PDFAdv Mater
September 2025
Research Center for Crystal Materials, CAS Key Laboratory of Functional Materials and Devices for Special Environmental Conditions, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, P. R. China.
The generation of coherent deep-ultraviolet (DUV) radiation via nonlinear frequency conversion remains a major scientific and technological challenge in modern optics. To date, only a very limited number of nonlinear optical (NLO) crystals-such as KBBF, ABF, and quartz-have been experimentally demonstrated to support measurable direct second-harmonic generation (SHG) at wavelengths of 177 nm or shorter. There is a pressing need to develop alternative materials or strategies that enable efficient frequency conversion in the DUV region.
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