Abstract: A method and a system for increasing the lifespan of a plasma obtained in the atmosphere. The method includes the following steps: emitting a femtosecond laser pulse, referred to as a first pulse, generating a column of plasma by the filamentation phenomenon, and emitting a second YAG laser pulse, focused by way of an axicon on a line in the plasma column, the energy of the photons of the second laser pulse being greater than the attachment energy of the electrons in the plasma to neutral molecules such as oxygen molecules. The duration of the second pulse is greater than the duration of the first pulse, and the delay between the two pulses is greater than one microsecond.

Abstract: A method and a system for increasing the lifespan of a plasma obtained in the atmosphere. The method includes the following steps: emitting a femtosecond laser pulse, referred to as a first pulse, generating a column of plasma by the filamentation phenomenon, and emitting a second YAG laser pulse, focused by way of an axicon on a line in the plasma column, the energy of the photons of the second laser pulse being greater than the attachment energy of the electrons in the plasma to neutral molecules such as oxygen molecules. The duration of the second pulse is greater than the duration of the first pulse, and the delay between the two pulses is greater than one microsecond.

Abstract: The invention relates to a method and device for machining a target using a femtosecond laser beam. The invention consists in taking advantage of the deterministic nature of the ablation threshold and the nonlinear dependence thereof through the use of amplitude or phase pupillary filtering using the polarising effect or any other technique in order to reduce significantly the machining dimensions obtained by focusing a laser beam in nanotechnologies. One such filtering process modifies the distribution of the intensity in the focal plane such as to reduce the maximum of the central component of the spectrum of laser pulses while maintaining the bright rings below the deterministic ablation threshold. The invention associates the femtosecond ablation technique with deterministic threshold and the apodisation technique.

Abstract: The invention relates to a non-linear optical filter capable of transmitting an electromagnetic pulse with a duration of less than about 1 picosecond, provided with means for generating an electromagnetic field E with a linear polarization from this pulse, and with a crystal C1 of cubic geometry capable of generating an electromagnetic field E?1 from E with a linear polarization orthogonal to that of E. It comprises means for generating at least one other electromagnetic field E?2 capable of producing constructive interferences with the electromagnetic field E?1.

Abstract: The invention relates to a non-linear optical filter capable of transmitting an electromagnetic pulse with a duration of less than about 1 picosecond, provided with means for generating an electromagnetic field E with a linear polarization from this pulse, and with a crystal C1 of cubic geometry capable of generating an electromagnetic field E?1 from E with a linear polarization orthogonal to that of E. It comprises means for generating at least one other electromagnetic field E?2 capable of producing constructive interferences with the electromagnetic field E?1.