2014 The effects of self, induced, and cross phase modulations on the generation of picosecond and femtosecond « white » laser pulses are reviewed. Recent measurements of cross and induced phase modulations are reported using femtosecond and picosecond laser pulses. Revue Phys. Appl. 22 (1987) -1694 DÉCEMBRE 1987, PAGE 1677

By applying the femtosecond laser ablation technique, we have simultaneously atomized and ionized large organic molecules on a solid substrate. This observation is in contrast with the photoionization of cyclic aromatic hydrocarbons by femtosecond laser in the gas phase where little fragmentation has been observed. Our result will promote the development of single-shot chemical analyses of isot...

We report on a single-state measurement of electrical conductivity of warm dense gold in the solid to plasma transition regime. This is achieved using the idealized slab plasma approach of isochoric heating of ultrathin samples by a femtosecond laser, coupled with femtosecond probe measurements of reflectivity and transmission. The experiment also reveals the time scale associated with the disa...

PURPOSE To compare the predictability of intrastromal tunnel depth creation for intrastromal corneal ring segments (ICRS) implantation between manual dissection and femtosecond laser using a high-resolution anterior segment optical coherence tomography (AS-OCT). METHODS This multicenter study included patients with keratoconus who had Ferrara-type ICRS implantation at Hospital de Braga using ...

The effects of femtosecond laser machining on surface characteristics and subsurface microstructure of a Nitinol alloy were studied. The femtosecond laser machining produced an average surface roughness of 0.2 μm. A re-deposited layer of 7 μm and a hardened layer of 70 μm were also resulted from the machining.

We report time-resolved studies using femtosecond laser pulses, accompanied by model calculations, that illuminate the difference in the dynamics of ultrashort pulsed laser ablation of different materials. Dielectrics are strongly charged at the surface on the femtosecond time scale and undergo an impulsive Coulomb explosion. This is not seen from metals and semiconductors where the surface cha...

A new terahertz (THz) source in air based on the bifilamentation of femtosecond laser pulses is reported. This THz radiation is 1 order of magnitude more intense than the transition-Cherenkov THz emission from femtosecond laser filaments reported recently and shows different angular and polarization properties. We attribute it to the emission from a bimodal transmission line created by two plas...

Gold nanorods have been found to change their shape after excitation with intense pulsed laser irradiation. The final irradiation products strongly depend on the energy of the laser pulse as well as on its width. We performed a series of measurements in which the excitation power was varied over the range of the output power of an amplified femtosecond laser system producing pulses of 100 fs du...

A femtosecond laser-based optical frequency synthesizer is referenced to an optical standard, and we use it to demonstrate the generation and control of the frequency of electromagnetic fields over 100 terahertz of bandwidth with fractional uncertainties approaching 1 part in 10(19). The reproducibility of this performance is verified by comparison of different types of femtosecond laser-based ...

The nonlinear absorption coefficient of As(2)S(3) glass has been measured to be 2.0 cm/GW for femtosecond pulses at 800 nm. Femtosecond laser structuring via two photon absorption in bulk As(2)S(3) glass by erasable and permanent photo-darkening is demonstrated using both holographic and direct multi-beam laser writing.