Mechanism of fine ripple formation on surfaces of (semi)transparent materials via a half-wavelength cavity feedback.

The mechanism of the fine ripples, perpendicular to laser polarization, on the surface of (semi)transparent materials with period smaller than the vacuum wavelength, λ, of the incident radiation is proposed and experimentally validated. The sphere-to-plane transformation of nanoplasma bubbles responsible for the in-bulk ripples accounts for the fine ripples on the surface of dielectrics and semiconductors. The mechanism is demonstrated for 4H:SiC and sapphire surfaces using 800 nm/150 fs and 1030 nm/300 fs laser pulses.

Spatial resonator solitons.

Spatial solitons can exist in various kinds of nonlinear optical resonators with and without amplification. In the past years different types of these localized structures such as vortices, bright, dark solitons, and phase solitons have been experimentally shown to exist. Many links appear to exist to fields different from optics, such as fluids, phase transitions, or particle physics.

Precursor forms of cavity solitons in nonlinear semiconductor microresonators.

We study the transverse nonlinear dynamics of bulk and multi-quantum well AlGaAs microresonators, in the mixed dispersive and saturable absorptive regime, slightly below the band-gap edge energy. With a Gaussian beam excitation we observe strongly localized states of various shapes, bright or dark in reflection. Their dynamics appears to be ruled by strong thermally induced nonlinear mechanisms, acting as a dressing mechanism for electronic nonlinearities.

Optical self-organization in bulk and multiquantum well GaAlAs microresonators.

We have observed optical patterns in GaAs/GaAlAs vertical-cavity microresonators. Rolls, rhombs, or hexagons were obtained depending on the wavelength detuning. We show that cavity thickness fluctuations contribute to pattern selection.