Archives June 2025

Alchemically-glazed plasmonic nanocavities using atomic layer metals: controllably synergizing catalysis and plasmonics

Shu Hu ,EricS.A.Goerlitzer ,QianqiLin Vyacheslav M. Silkin,& Jeremy J. Baumberg, Bart de Nijs

https://doi.org/10.1038/s41467-025-58578-9

Plasmonic nanocavities offer exceptional confinement of light, making them effective for energy conversion applications. However, limitations with stability, materials, and chemical activity have impeded their practical implementation. Here we integrate ultrathin palladium (Pd) metal films from sub- to few- atomic monolayers inside plasmonic nanocavities using underpotential deposition. Despite the poor plasmonic properties of bulk Pd in the visible region, minimal loss in optical field enhancement is delivered along with Pd chemical enhancement, as confirmed by ab initio calculations. Such synergistic effects significantly enhance photocatalytic activity of the plasmonic nanocavitiesaswelasphotostabilityby suppressing surface atom migration. We show the atomic alchemical-glazing approach is general for a range of catalytic metals that bridge plasmonic and chemical catalysis, yielding broad applications in photocatalysis for optimal chemical transformation.

Fig. Alchemical space for atomic-glazing on Au substrates.

congratulation to Our new paper 🎉

M.Asadolah Salmanpour, M. Mosleh & S. M. Hamidi^*
Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran.

This study presents a dual-frequency modulation scheme in which both optical and microwave fields are simultaneously modulated in a microwave–optical double resonance system within a hot rubidium vapor cell. The combined modulation produces harmonic spectral features at the sum and difference of the individual modulation frequencies, indicating nonlinear coupling between the fields. Experimental results reveal that this approach enables modulation of atomic population dynamics and facilitates efficient population transfer between hyperfine levels. The observed frequency mixing highlights the system’s sensitivity to dual modulation and suggests its potential for enhancing the spectral control of atomic transitions. These findings may support future developments in atomic clocks, high-precision magnetometers, and quantum information processing systems.

Two-photon polymerization for biological applications

Alexander K. Nguyen and Roger J. Narayan

Materials Today Volume 20,Number 6 July/August 2017

UNC/NCSU Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695-7115, USA

https://doi.org/10.1016/j.mattod.2017.06.004

Two-photon polymerization (2PP) leverages the two-photon absorption (TPA) of near-infrared (NIR) radiation for additive manufacturing with sub-diffraction limit resolution within the bulk of a photosensitive material. This technology draws heavily on photosensitive polymers from the microelectronics industry, which were not optimized for TPA or for biocompatibility. 2PP with sub 100 nm resolution has been repeatedly demonstrated; however, this level of fabrication resolution comes at the expense of long fabrication times. Manufacturing of medical devices beyond surface texturing would be prohibitively slow using the current state of the art 2PP technology. Current research intoTPA-sensitivephotopolymerswithgoodbiocompatibilityandholographicprojectionsusingspatial light modulators address current technological limitations by providing materials specifically formulated for biological applications and by making better use of available laser power for applications in which nanoscale resolution is not required.

Optical setup of a femtosecond laser imaging and microfabrication system, which is capable of fluorescence lifetime imaging microscopy. Reprinted from Ref.