Abstract: The present invention relates to a device for amplifying a multi-wavelength laser beam, comprising: a. a first active laser medium having a front face and a rear face which is reflective, inclined with respect to each other at a first non-zero inclination, and b. a second active laser medium having a front face suitable for receiving the beam reflected by the rear face and refracted by the front face of the first active laser medium, and a reflective rear face, inclined with respect to each other at a second non-zero inclination, the first inclination, the second inclination and the orientation of the second active laser medium being such that the sub-beams of each wavelength, forming the output beam of the second active laser medium, are parallel to each other at the output of the second active laser medium.

Abstract: The present invention relates to a device for amplifying a multi-wavelength laser beam, comprising: a. An active laser medium having a front face suitable for receiving the beam to be amplified each time the same passes through the active laser medium, and a reflective rear face inclined with respect to the front face, the beam reflected by the rear face and refracted by the front face during the n-th pass being called the n-th useful beam, and b. a first optical return unit arranged along the path of the first useful beam and configured for returning the first useful beam on the front face for a second pass through the active laser medium so that the sub-beams of each wavelength, forming the second useful beam, are parallel to each other at the end of the second pass.

Abstract: A device for amplifying a multi-wavelength pulsed laser beam is provided, which comprises: a solid amplifying medium with two planer faces, a front face and a reflecting rear face; and a device for cooling the amplifying medium by the rear face. The front face of the amplifying medium is tilted relative to its rear face by a first non-zero tilt and the device further comprises a trapezoidal prism, with an input face and an output face which form between them a second non-zero tilt, the first and second tilts being such that the beams of each wavelength are parallel to one another at the output of the prism.

Abstract: A device for amplifying a multi-wavelength pulsed laser beam is provided, which comprises: a solid amplifying medium with two planer faces, a front face and a reflecting rear face; and a device for cooling the amplifying medium by the rear face. The front face of the amplifying medium is tilted relative to its rear face by a first non-zero tilt and the device further comprises a trapezoidal prism, with an input face and an output face which form between them a second non-zero tilt, the first and second tilts being such that the beams of each wavelength are parallel to one another at the output of the prism.