Device for the compression of laser pulses of the order of the nanosecond and consequent generation of ultrashort pulses of the order of one hundred femtoseconds

A device for the compression of laser pulses of the order of the nanosecond into ultrashort pulses down to durations of the order of 100 femtoseconds wherein the oscillator is provided with a ring path in which the following are provided:

• a first and a second non-overlapping transmission band-pass filter;
• optically transparent means with non-linear Kerr coefficient χ(3) different from zero configured to achieve a spectral broadening by self-phase modulation of the signal transiting through these means;
• an active optical waveguide that produces a positive gain;
• a node configured to receive a trigger signal designed to establish the operation of the oscillator;
• further optically transparent non-linear means with non-linear Kerr coefficient χ(3) different from zero;
• an isolator arranged at any one position along the ring path, configured for a specific direction of propagation of the light radiation within the ring path;
• a second optical amplifier placed between the further optically transparent non-linear means;
• a trigger signal generating device, which is characterised by comprising:
• a laser source, configured to generate a laser pulse having a duration of the order of the nanosecond, which is required to trigger the oscillator;
• a coupling system designed to introduce the laser pulse into a waveguide made of an optically transparent material characterised by a non-linear Kerr coefficient χ(3) different from zero, which is configured to achieve two distinct effects in order to spectrally broaden the pulse of the trigger laser, and precisely:
• a) self-phase modulation;
• and b) four-wave mixing;
• the output of the waveguide supplying the trigger signal to said node.