Topology-optimized distributed 3d anisotropic Raman emission
Massachusetts Institute of Technology（麻省理工学院）；Vrije Universiteit Amsterdam（阿姆斯特丹自由大学）；Rice University（莱斯大学）；Duke University（杜克大学）；Technical University of Denmark（丹麦技术大学）
Ian M. Hammond, Pengning Chao, Henry O. Everitt, Rasmus E. Christiansen, Alan Edelman, Francesc Verdugo, Steven G. Johnson
Topology optimization (TO) of 3D surface-enhanced Raman scattering (SERS) substrates faces challenges in managing field singularities and modeling orientation-averaged anisotropic molecules. We present 3D TO for manufacturable SERS substrates that maximize spatially averaged signals from randomly oriented, anisotropic molecules in both elastic and inelastic scattering. A new trace formulation provides a closed-form rotational average of anisotropic Raman tensors, which are not equivalent to isotropic molecules because of tensor nonlinearity. Optimized silver and Si3N4 devices show that lengthscale constraints are sufficient to suppress designs that rely on unphysical mathematical field divergences at sharp corners. Metallic designs deliver broadband enhancement and remain robust to typical Raman shifts, whereas dielectric designs yield narrower, quality-factor-limited gains that are inferior to metallic designs for quality factors below about 500. Our approach readily incorporates additional physics, such as a nonlinear damage model. Together, these results provide a practical route to improved manufacturable SERS substrates and extend naturally to other distributed-emitter design problems.
Numerically optimized FROG results for the study of red-shifted spectra in multi-frequency Raman generation
IIT Madras（印度理工学院马德拉斯分校）；University of Waterloo（滑铁卢大学）；Meta；Indian Institute of Science（印度科学学院）；IIT Bhubaneswar（印度理工学院布巴内斯瓦尔分校）；RWTH Aachen University（亚琛工业大学）
Hyperbolic-enhanced Raman scattering in van der Waals MoOCl2: from Fano resonances to picomolar detection
XPANCEO；University of Chemistry and Technology Prague（布拉格化工大学）；National Graphene Institute (NGI), University of Manchester（曼彻斯特大学国家石墨烯研究所）；National University of Singapore（新加坡国立大学）
Optimized near-field optical response via adaptive tip illumination
Friedrich Schiller University Jena（耶拿弗里德里希·席勒大学）；Leibniz Institute of Photonic Technology (IPHT)（莱布尼茨光子技术研究所）；Shanghai Institute of Optics and Fine Mechanics（上海光学精密机械研究所）；Hangzhou Institute of Optics and Fine Mechanics（杭州光学精密机械研究所）
Background-free time-resolved coherent Raman spectroscopy (CSRS and CARS): heterodyne detection of low-energy vibrations and recognition of excited-state contributions
