A method and system for amplifying seed laser radiation which is irradiated along an irradiation direction into a lasing amplification medium has a transverse seed laser intensity profile that is transformed into a plateaued input intensity profile by a transformer element on the irradiation side.

A fiber coupled modular laser system comprises a laser oscillator, at least one fiber pre-amplifier, and at least one free space solid state power amplifier. The output of the laser oscillator is fiber coupled with the input of the at least one fiber pre-amplifier or the at least one free space solid state power amplifier. The output or the input of the at least one fiber pre-amplifier is fiber coupled with the input or the output of the at least one free space solid state power amplifier.

Techniques are provided for scaling the average power of high-energy solid-state lasers to high values of average output power while maintaining high efficiency. An exemplary technique combines a gas-cooled-slab amplifier architecture with a pattern of amplifier pumping and extraction in which pumping is continuous and in which only a small fraction of the energy stored in the amplifier is extracted on any one pulse. Efficient operation is achieved by propagating many pulses through the amplifier during each period equal to the fluorescence decay time of the gain medium, so that the preponderance of the energy cycled through the upper laser level decays through extraction by the amplified pulses rather than through fluorescence decay.

A laser amplifier module having an enclosure includes an input window, a mirror optically coupled to the input window and disposed in a first plane, and a first amplifier head disposed along an optical amplification path adjacent a first end of the enclosure. The laser amplifier module also includes a second amplifier head disposed along the optical amplification path adjacent a second end of the enclosure and a cavity mirror disposed along the optical amplification path.

A method and system for amplifying seed laser radiation which is irradiated along an irradiation direction into a lasing amplification medium has a transverse seed laser intensity profile that is transformed into a plateaued input intensity profile by a transformer element on the irradiation side.

Techniques are provided for scaling the average power of high-energy solid-state lasers to high values of average output power while maintaining high efficiency. An exemplary technique combines a gas-cooled-slab amplifier architecture with a pattern of amplifier pumping and extraction in which pumping is continuous and in which only a small fraction of the energy stored in the amplifier is extracted on any one pulse. Efficient operation is achieved by propagating many pulses through the amplifier during each period equal to the fluorescence decay time of the gain medium, so that the preponderance of the energy cycled through the upper laser level decays through extraction by the amplified pulses rather than through fluorescence decay.

A laser amplifier module having an enclosure includes an input window, a mirror optically coupled to the input window and disposed in a first plane, and a first amplifier head disposed along an optical amplification path adjacent a first end of the enclosure. The laser amplifier module also includes a second amplifier head disposed along the optical amplification path adjacent a second end of the enclosure and a cavity mirror disposed along the optical amplification path.

Laser-apparatus includes a fiber-MOPA arranged to deliver amplified seed optical pulses having a wavelength of about 1043 nanometers to a multi-pass ytterbium-doped yttrium aluminum garnet solid-state optical amplifier for further amplification.

The described methods and devices minimize or reduce the effects of the leading amplified spontaneous emission component of an optical pulse in optical multi-pass amplifier systems. One multi-pass optical amplifier includes a gain medium positioned to receive a pump laser, and to receive an optical pulse having a main component and one or both of a leading or a trailing component. The optical amplifier also includes one or more reflectors positioned at a first side or at a second side of the gain medium that allow multi-pass propagation of the optical pulse through the gain medium. The one or more reflectors are positioned to allow the main component of the optical pulse to traverse through the gain medium in a first pass before the leading component of the optical pulse reaches the gain medium in a second pass through the gain medium.

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.