English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We combine scattering theory, Fourier, traveling wave and asymptotic analysestogether with numerical simulations to present interesting and practicallyuseful properties of femtosecond pulse interaction with thin films. Thedispersive material is described by a single resonance Lorentz model and itsnonlinear extension with a cubic Duffing-type nonlinearity. A key feature ofthe Lorentz dielectric function is that its real part becomes negative betweenits zero and its pole, generating a forbidden region. We illustrate numericallythe linear interaction of the pulse with the film using both scattering theoryand Fourier analysis. Outside this region we show the generation of a sequenceof pulses separated by round trips in the Fabry-Perot cavity due to multiplereflections. When the pulse spectrum is inside the forbidden region, we observetotal reflection. Near the pole of the dielectric function, we demonstrate theslowing down of the pulse (group velocity tending to zero) in the medium thatbehaves as a high-Q cavity. We use the combination of analysis and simulationsin the linear regime to validate the delta function approximation of the thinlayer; this collapses the forbidden region to a single resonant point of thespectrum. We also study the single cycle pulse interaction with a thin film andshow three distinct types of reflection: half-pulse, sinusoidal wave train andcosine wavelet. Finally we analyze the influence of a strong nonlinearity andobserve that the film switches from reflecting to trasparent.

Scattering of a short electromagnetic pulse from a Lorentz-Duffing film: theoretical and numerical analysis