L. Mees

Time-resolved scattering diagrams for a sphere illuminated by plane wave and focused short pulses

Abstract Relying on a generic formulation of a generalized Lorenz–Mie theory for a particle illuminated by laser pulses, we present time-resolved scattering diagrams for a 100-μm-diameter sphere illuminated by a 100 fs pulse, in the cases of a plane wave lateral extension and of a focused laser beam. The response of the sphere to a single pulse takes the form of a train of pulses which are associated with different independent scattering events (reflection, diffraction, refraction, etc.).

Generalized Lorenz–Mie theory for infinitely long elliptical cylinders

A generalized Lorenz–Mie theory for infinite elliptical cylinders is presented. This theory describes the interaction between arbitrary shaped beams and infinitely long cylinders having an elliptical cross section.

Interaction between femtosecond pulses and a spherical microcavity: internal fields

This paper is devoted to the spatio-temporal behaviour of internal fields created by an ultrashort pulse of light inside a spherical cavity. The characteristic length of the pulse in free space is shorter than the cavity diameter, leading to a temporal separation of optical modes. The elastic internal intensity is displayed versus time.

Two-photon absorption and fluorescence in a spherical micro-cavity illuminated by using two laser pulses: numerical simulations

This paper is devoted to two photons excited fluorescence in a spherical micro-cavity. We describe the internal fields created when two ultra-short pulses of light illuminate a spherical micro-cavity, with the time delay between the two pulses as a parameter.

Partial-wave description of shaped beams in elliptical-cylinder coordinates

We present the most general framework, in terms of distributions, for describing a shaped electromagnetic beam in elliptical-cylinder coordinates. This framework is illustrated by investigating the case of a first-order Gaussian beam.

Validity of the elliptical cylinder localized approximation for arbitrary shaped beams in generalized Lorenz–Mie theory for elliptical cylinders

A so-called elliptical cylinder localized approximation theory allowing one to speed up the evaluation of beam shape distributions in generalized Lorenz–Mie theory for infinitely long cylinders with elliptical cross sections has been previously introduced and, in the case of Gaussian beams, rigorously justified. The validity of this approximation for arbitrary shaped beams is examined.

Numerical predictions of microcavity internal fields created by femtosecond pulses, with emphasis on whispering gallery modes

This paper is devoted to the spatio-temporal behaviour of internal fields created by an ultrashort pulse of light inside a glass spherical cavity (n = 1.6). The characteristic length of the pulse in free space is shorter than the cavity diameter, leading to a temporal separation of optical modes. The elastic internal intensity is displayed versus time and the influence of the microcavity refractive index is discussed by comparison with the case of a water droplet, which has been previously published. Particular attention is devoted to whispering gallery modes created in the cavity.

Surface waves/geometrical rays interferences : numerical and experimental behaviour at rainbow angles

Abstract This article is devoted to the study of the behaviour of interferences between geometrical rays and surface waves. The measurement of surface waves is a potential key for very accurate characterization of particle surface and sphericity. The use of a generalized Lorenz–Mie theory provides new insights on involved phenomena.

Partial-wave expansions of higher-order Gaussian beams in elliptical cylindrical coordinates

Partial-wave expansions of higher-order Gaussian beams are presented in elliptical cylindrical coordinates. They involve beam shape distributions which are linear combinations of the Dirac distribution and of its derivatives with test functions based on the Mathieu functions.