Consiglio Nazionale Delle Ricerche

Datalogic Automation S.r.l.

Orazio Svelto

Sandro De Silvestri

Marco Tagliaferri

Fabio Cannone

Paolo Laporta

Mauro Nisoli

A laser system for the marking of metallic and non-metallic materials comprising a laser oscillator (), characterized in that said laser oscillator () comprises: an active optical means () of the crystal laser type, a laser pump () to provide a pump energy to said active optical means (); a mirror () disposed upstream said active optical means (); an optical switch (), apt to provide a pulsed laser beam, disposed downstream said active optical means (); a mode adaptor () coupled to said optical switch (); a predetermined length single-mode optical fiber (), coupled to said mode adapter (); a Bragg Grating type reflector coupled to said optical fiber ().

Laser system for the marking of metallic and non-metallic materials

Our invention achieves spectral broadening of an input pulse by propagating it through a hollow fiber filled with a noble gas. The output pulse is then compressed to a shorter duration by passing it through an optical system consisting of phase dispersive elements. In a preferred embodiment, the input pulse is generated by a mode-locked laser, amplified and then subsequently compressed to produce an input pulse of high peak power. This input pulse is then focused into a hollow cylindrical fiber made of fused silica and mounted inside a pressure vessel filled with noble gas. The optics are designed to match the spatial mode volume of the input pulse to that of the entrance aperture of the hollow fiber. Light is constrained to propagate down the hollow fiber and generates additional bandwidth through self-phase modulation as it interacts with the gas contained therein. The spectrum of the pulse after propagation through the gas is frequency chirped. A portion or all of this bandwidth is then compressed using prisms to produce a laser pulse of shorter duration than the input pulse.

Capillary compressor

Laser apparatus which generates a uniform laser beam of minimum divergence and maximum intensity includes a resonator cavity having a laser source and first and second mirror devices disposed on opposite sides of the source. The first mirror reflects pumped laser light within the cavity. The second mirror includes two mirror elements, both of which also reflect pumped laser light within the cavity. The two mirror elements of the second mirror device have specific configurations and a selected distance therebetween to cause the generation of a uniform output laser beam. That is, the laser light reflected from the second mirror element is dephased with respect to laser light reflected from the first mirror element by a whole number of periods of the laser light at the centerline between the first and second mirror elements. Also, laser light reflected from the second mirror is dephased with respect to laser light reflected from the first mirror by a whole number plus a half of the laser light period at the lateral edges of the first and second mirror elements.

Growing community of inventors

Segrate, Italy

Orazio Svelto