A. Le Floch

Jones matrices of a tilted plate for Gaussian beams

The Jones matrix of a tilted plate is theoretically and experimentally described, taking into account the contribution of the successive internal reflections of the incident fundamental TEM(00) Gaussian beam. This induces variations of up to 10% of the transmission coefficients of the Jones matrix with angle of incidence. The consequence of the influences on the walkoff and the internal interference effects of the characteristics ofthe plate and of the incident beam, especially its mode size and its radius of curvature, leads to important different variations of the Jones matrix. of such a plate however, we show that for a given Gaussian beam the Jones matrix of the plate does not depend on its position along the beam propagation axis, in spite of the variations of mode size and radius of curvature whose effects compensate mutually. The Jones matrix of such a plate used in a laser cavity containing a diffracting aperture is also investigated. In every case, good agreement is observed between theory and experiment.

Experimental evidence of single round-trip oscillation in polarization self-modulated vertical-cavity surface emitting lasers

The polarizations and frequencies of the two eigenstates of a vertical cavity surface emitting laser with an external cavity containing a quarter-wave plate are theoretically and experimentally analyzed. It is shown that the polarizations of these eigenstates are fixed by the neutral axes of the quarter-wave plate. The optical pulses at a frequency equal to a half of the free spectral range of the external cavity, observed through a linear polarizer, are due to beats between the two eigenstates. All these features show that such polarization self-modulated lasers oscillate in a single round trip.

Study of the dynamical behaviour of the polarization of a quasi- isotropic laser in the earth magnetic field

Abstract High-gain quasi-isotropic lasers are shown to be very sensitive probes of the Earth magnetic field. The rate of rotation of the polarization is shown to exhibit an Adler-type evolution with the azimuth of the laser propagation axis, with a locking region depending on the controlled loss-anisotropies introduced in the cavity. The evolution of this rotation rate with the excitation and the detuning is also investigated. It is also shown that the sensitivity of the laser to the Earth magnetic field increases when extra losses are introduced in the cavity, leading to a sensitivity of a few hundredths of Gauss. In every case, a good agreement is observed between experiments and theory.

Measurement of the Transverse Displacement at Total Reflection by Helicoidal Laser Eigenstates

The transverse displacement at total reflection of a laser beam is experimentally investigated for only one reflection of the circularly polarized beams. The differential experimental method uses the high sensitivity of the helicoidal eigenstates of a laser to measure, for the first time, the intracavity transverse shift for various angles of incidence. The measurements are consistent with our calculations of the transverse shift for circularly polarized light.

Polarization slaving mechanisms in vectorial bistable lasers

The basic mechanisms of external all-optical control of polarization bistabilities are isolated in one- and two-frequency systems. Induced rotation and induced inhibition mechanisms by vectorial injection in lasers are theoretically predicted and experimentally shown in both systems. The sensitivity of the vectorial systems leads to subfemtojoule switching energies, which correspond to the theoretical threshold values. A reduction by four orders of magnitude compared to the lowest energy demonstrated in scalar passive systems is obtained.

ANGULAR GOOS-HANCHEN EFFECT IN CURVED DIELECTRIC MICROSTRUCTURES

A macroscopic angular Goos-Hänchen effect at total reflection on curved interfaces is studied experimentally. The results are compared with the complex-angular-momentum model of quasi-critical scattering. An extremum in angular deflection, which has not yet been predicted by any theory other than exact Mie scattering computations, is identified at low size parameters.

A dipole interaction model for magnetochiral birefringence

We have developed a classical model to investigate the magnetochiral birefringence of an isotropic chiral medium submitted to a longitudinal magnetic field. This model, which is an extension of the atom dipole interaction model, yields direct calculations from the polarizabilities and positions of the atoms of the considered molecules. The numerical values obtained for the magnetochiral birefringence, as well as for the optical activity and Faraday rotation, are supported by the previously published experimental results on limonene, proline, and tartaric acid.

Measurement of small rotations by eigenvector flips in a quasi-isotropic Fabry-Perot

A novel small rotation or small birefringence measurement scheme based on the dynamics of the helicoidal eigenstates of a passive Fabry–Perot cavity with two quarter‐wave plates is described. When the system is inserted between two crossed polarizers, the sensitivity of the method is shown to be proportional to the square of the finesse of the cavity. For a finesse of 50, the observed noise floor corresponds to an estimation of the minimum detectable small rotation of 3×10−8 rd. We discuss possible improvements and potential possibilities of the method.

Lamb dip asymmetry in lasers with plane-parallel resonators

The Lamp dip asymmetry due to linear or nonlinear lenslike effects is investigated in lasers with plane-parallel resonators. The experiments are performed using diffracted light spectroscopy. It is shown that the frequency-dependent diffraction losses are essential in determining Lamb dip asymmetry, regardless of the origin of the lenslike effects.

Direct observation of a photon spin-induced constant acceleration in macroscopic systems

The use of a spider silk allows the direct observation of the dynamics induced by the transfer of angular momentum of laser light in a Beth-type experiment. In the optical domain, a uniform angular acceleration of a macroscopic object is demonstrated in agreement with the expected equation of motion. The intrinsic angular momentum exerts a stable torque thats modulus can be continuously adjusted from 0to10−12Nm by changing the optical power. Moreover, a macroscopic no-node mirror is proposed to improve the optical angular momentum transfer in micro-manipulation in the context of optical tweezers.