Extinction Cross-section Spectra Research Articles

Optical response of a single gold nanoparticle

Optical detection and spectroscopy of single gold nanoparticles using the spatial-modulation spectroscopy technique is described, focusing on the connection between the nanoparticle and environment parameters with the measured linear optical extinction spectrum. Characterisation of the size, shape and orientation on the substrate of a nanoparticle through quantitative determination of its optical extinction cross-section spectrum is illustrated in the case of gold nanospheres and nanorods. Extension of this technique to ultrafast nonlinear spectroscopy of a single gold nanoparticle is also discussed.

Correlation between the Extinction Spectrum of a Single Metal Nanoparticle and Its Electron Microscopy Image

The absolute extinction cross-section spectrum of a single nanoparticle measured using spatial modulation spectroscopy (SMS) is correlated with its transmission electron microscopy (TEM) image. The sizes of quasi-spherical particles obtained by the two methods are found to be in good quantitative agreement. The possibilities opened up by combination of these methods for precise correlation of the optical response of a nanoobject with its geometry are illustrated in the case of a pair of interacting nanoparticles (dimer).

Mie computational test of the extinction cross-section sum rules and optical moments for large dielectric spheres and shells

Numerically determined extinction cross-section spectra of large spherical particles containing spectral and geometrical inhomogeneities are used to test the general nature of the extinction cross-section sum rules and optical moments. The results are independent of the scattering details.

Extinction sum rule and optical moment for an ellipsoidal particle of arbitrary size

The frequency dependent extinction cross section of an ellipsoidal particle of arbitrary size is examined from the perspective of sum rules and optical moments. An extinction strength sum rule is found which directly relates the effective number of electrons in the scatterer to the integral over the extinction cross section spectrum, independent of particle shape. In addition, the characteristic frequency for the extinction cross section spectrum is found to be independent of particle size.