Abstract: The method comprises A method includes steps for creating at least two replicas of an input pulse to be characterised, varying the relative amplitude of the two replicas within a range, creating a nonlinear signal at each case of said amplitude variation, measuring the spectra of the nonlinear signals and recovering the spectral amplitude and phase of the input pulse with a proper algorithm. The system includes a replicator for creating at least two replicas of the input pulse and varying their relative amplitude within a range of relative amplitudes, a nonlinear medium, which obtains a nonlinear signal for each relative amplitude, and an analyzer, associated to the nonlinear signal for measuring and characterising spectrally each nonlinear signal.

Abstract: An apparatus and a method for in-line measurement of laser pulses with time-dependent polarization are described, which make possible to carry out in-line measurement of laser pulses whose polarization depends on time. For this, one or more polarization projections are selected: the spectrometer detects the projection on the extraordinary propagation axis of a birefringent system to measure the spectrum in that component, also the projection on the ordinary propagation axis, to measure the spectrum in that component, and finally a projection in an intermediate direction that allows to measure the interference spectrum between the two components. The method allows extracting the temporal evolution of the pulse and its polarization state as a function of time, spectral amplitudes and phases of the various polarization projections of the beam.

Abstract: The present application relates to a method and system for characterization and compression of ultrashort pulses. It is described a flexible self-calibrating dispersion-scan technique and respective system to characterize and compress ultrashort laser pulses over a broad range of pulse parameters, where previous knowledge of the amount of dispersion introduced for each position or step of the compressor is not required. The self-calibrating d-scan operation is based on the numerical retrieval of the spectral phase of the pulses using an optimization algorithm, where the spectral phase is treated as a multi-parameter unknown variable, and where the unknown dispersion of the dispersion scanning system is described by a theoretical model of its functional dependence on the compressor position.

Abstract: The present application relates to a method and system for characterization and compression of ultrashort pulses. It is described a flexible self-calibrating dispersion-scan technique and respective system to characterize and compress ultrashort laser pulses over a broad range of pulse parameters, where previous knowledge of the amount of dispersion introduced for each position or step of the compressor is not required. The self-calibrating d-scan operation is based on the numerical retrieval of the spectral phase of the pulses using an optimization algorithm, where the spectral phase is treated as a multi-parameter unknown variable, and where the unknown dispersion of the dispersion scanning system is described by a theoretical model of its functional dependence on the compressor position.

Abstract: An apparatus and a method for in-line measurement of laser pulses with time-dependent polarization are described, which make possible to carry out in-line measurement of laser pulses whose polarization depends on time. For this, one or more polarization projections are selected: the spectrometer detects the projection on the extraordinary propagation axis of a birefringent system to measure the spectrum in that component, also the projection on the ordinary propagation axis, to measure the spectrum in that component, and finally a projection in an intermediate direction that allows to measure the interference spectrum between the two components. The method allows extracting the temporal evolution of the pulse and its polarization state as a function of time, spectral amplitudes and phases of the various polarization projections of the beam.