Abstract: The present invention relates to a high-power femtosecond pulsed laser, the laser including: a source able to generate a train of input laser pulses having an envelope frequency and a carrier frequency; a chirped pulse amplification unit; and, a unit for controlling the phase drift between the envelope frequency and the carrier frequency of the output laser pulses. According to the invention, the unit for controlling the phase drift between the envelope frequency and the carrier frequency includes electro-optical phase-modulation unit that are placed on an optical path of the chirped pulse amplification unit in order to stabilize the phase drift between the envelope frequency and the carrier frequency of the output laser pulses as a function of time.

Abstract: The present invention relates to a high-power femtosecond pulsed laser, the laser including: a source able to generate a train of input laser pulses having an envelope frequency and a carrier frequency; a chirped pulse amplification unit; and, a unit for controlling the phase drift between the envelope frequency and the carrier frequency of the output laser pulses. According to the invention, the unit for controlling the phase drift between the envelope frequency and the carrier frequency includes electro-optical phase-modulation unit that are placed on an optical path of the chirped pulse amplification unit in order to stabilize the phase drift between the envelope frequency and the carrier frequency of the output laser pulses as a function of time.

Abstract: A device (1) for correcting the amplitude/frequency characteristic of an input signal (FI), particularly from transmission cables (40), having a minimal frequency f1, a center frequency f0 and a maximal frequency f2, the input signal (FI) having an attenuation as a function of frequency characteristic that increases between f1 and f2, the correction device (1) supplying a corrected output signal (). The correction device includes two cascaded filters (41, 42), the first of the filters receiving the input signal (FI) and supplying a filtered signal (SFI) to the second of the filters, the second of the filters supplying the corrected output signal (). One of the filters is a band-stop filter (41) having a center frequency f3 less than or equal to f1, the other of the filters being a band-pass filter (42) having a center frequency f4 greater than or equal to f2. The center frequencies f3 and f4 satisfy the equation:f3.times.f4=f0.sup.

Abstract: A demodulator stage for direct demodulation of a phase quadrature modulated signal provides two baseband signals and comprises a matched 900.degree. coupler to which the modulated signal is fed and supplying two phase quadrature modulated signals. Two low-noise amplifiers with identical specifications each receive one of the phase quadrature modulated signals and supply an amplified signal. Two mixers each receive one of the amplified signals and a common local oscillator signal and supply the baseband signals. The 90.degree. coupler, the low-noise amplifiers and the two mixers can be integrated into the same MMIC. One application is to a receiver for frequency evasive phase quadrature modulated signals.

Abstract: An estimator for estimating the amplitude/frequency characteristic of a source signal from which baseband components i and q which are applied to the inputs of said estimator are derived by demodulation using two signals having orthogonal phases. The estimator includes a combiner for generating complex components i+j.multidot.q and q+j.multidot.i from the components i and q and evaluates the relative amplitudes of the complex components in order to produce a coefficient representative of the amplitude/frequency characteristic of the source signal. The invention can be used to implement a frequency equalizer whose estimator operates in the baseband, the estimator possibly driving a transversal filter operating at the intermediate frequency or at the microwave frequency.

Abstract: In a veneer lathe comprising a cutting slide and an anti-buckling device which are pressed by actuating means against a workpiece held between said lathe's rotating end chucks and wherein said cutting slide and anti-buckling device are guided relative to the stationary frame of said lathe along converging working planes forming an upwardly opening obtuse angle of substantially 120.degree., the improvement wherein said working planes are bisected by a plane substantially vertical to and intersecting the rotational axis of the rotating workpiece.