Related Experiment Video
Updated: May 27, 2026
09:33
Monitoring Conformational Dynamics of Single Unmodified Proteins using Plasmonic Nanotweezers
Published on: March 21, 2025
Rational design of ligand-free Rh-OsNanotrees for plasmonic tip localization and advanced third-order nonlinear
S Nandagopal1, A Vasantharaj2, M Dharmalingam3
1Department of Computer Science and Engineering, Nandha College of Technology, Erode, Tamil Nadu, 638052, India. asnandu@gmail.com.
Scientific Reports
|May 25, 2026
Summary
Ligand-free Rhodium-Osmium nanostructures exhibit exceptional nonlinear optical properties and stable plasmonic responses. These nanostructures show promise for advanced applications in photonics and optoelectronics due to their enhanced light-matter interactions.
Area of Science:
- Materials Science
- Nanotechnology
- Optics
Background:
- Developing advanced nanomaterials with superior nonlinear optical (NLO) properties is crucial for next-generation photonic devices.
- Plasmonic nanostructures offer unique light-matter interaction capabilities, but stability and performance often need improvement.
Purpose of the Study:
- To design and synthesize novel ligand-free Rhodium-Osmium (Rh-Os) nanostructures with enhanced third-order NLO properties.
- To investigate the stability and localized plasmonic responses of these nanostructures for potential applications.
Main Methods:
- Surfactant-free co-reduction synthesis of Rh-Os nanostructures.
- Characterization using HR-TEM, EDS mapping, and XRD analysis.
- Optical measurements including UV-Vis-NIR absorption, Z-scan, and two-photon absorption.
- Finite-difference time-domain (FDTD) simulations and electron energy-loss spectroscopy (EELS).
Main Results:
- Synthesized Rh-Os nanostructures exhibited ultrasharp tips (6-10 nm radius) and high aspect ratios.
- High specific surface area (127.4 m²/g) promoted strong light-matter interactions.
- Observed dual localized surface plasmon resonances (LSPRs) at ~432 nm and ~691 nm.
- Achieved localized field enhancements exceeding 180× at tip sites.
- Demonstrated a large nonlinear refractive index (n₂ ≈ 3.1 × 10⁻¹³ cm²/W) and third-order susceptibility (χ³ ≈ 8.4 × 10⁻¹⁰ esu).
- Exhibited a high optical damage threshold (2.3 J/cm²) and a two-photon absorption coefficient of 4.6 cm/GW.
Conclusions:
- Ligand-free Rh-Os nanostructures possess superior third-order nonlinear optical properties and stable tip-localized plasmonic responses.
- The unique structural and optical characteristics make them highly suitable for thin-film optical modulators.
- These nanostructures hold significant potential for applications in ultrasonic photonics, optoelectronics, and nonlinear sensing.
