An optical material including: a silica host; and a Praseodymium dopant; wherein the Praseodymium atoms are configured to form nanoclusters in the silica host. In addition, the optical material may include an Ytterbium co-dopant. The nanoclusters include Ge, Te, Ta, Lu and/or F, Cl to minimize multi-phonon quenching. Moreover, the nanoclusters may be encapsulated in a low phonon energy shell to minimize energy transfer to the host matrix.

Disclosed herein is a method comprising injecting light of a first wavelength .sub.1 into a wavelength division multiplexer; injecting light of a second wavelength .sub.2 into the wavelength division multiplexer; combining the light of the first wavelength .sub.1 and the light of the second wavelength .sub.2 in the wavelength division multiplexer to produce light of a third wavelength .sub.3; and reflecting the light of the third wavelength .sub.3 in a dual-Brillouin peak optical fiber that is in communication with the wavelength divisional multiplexer; wherein the dual-Brillouin peak optical fiber has at least two Brillouin peaks, such that an amplitude A.sub.1 of at least one of said Brillouin peaks is within 50% to 150% of an amplitude A.sub.2 of another Brillouin peak 0.5A.sub.2A.sub.11.5A.sub.2; wherein the dual-Brillouin peak optical fiber generates a Brillouin dynamic grating that reflects an improved back-reflected Brillouin signal of the combined light.

An optical fiber for a fiber laser includes a core to which a rare-earth element is added, a first cladding formed around the core; and a second cladding formed around the first cladding, and excitation light is guided from at least one end of the first cladding to excite the rare-earth element to output a laser oscillation light. An addition concentration of the rare-earth element to the core is different in a longitudinal direction of the optical fiber for a fiber laser, and a core diameter and a numerical aperture of the optical fiber for a fiber laser are constant in the longitudinal direction of the optical fiber for a fiber laser.

A high-power Raman fiber laser includes: a seed laser; a plurality of pump lasers, each including a cladding and comprising of thulium-doped fiber laser (TDFL) and configured to operate in a 1935-2020 nm spectral window; a pump/seed combiner to combine outputs of the pump lasers and output of the seed laser and having a tapered portion including a cladding; and a Raman fiber amplifier having a core and a cladding surrounding the core, the seed laser is launched into the core, and pump laser output beams are launched into the cladding, to amplify the seed laser to produce an amplified output signal, and a brightness of the cladding of the Raman fiber amplifier is matched to a combined brightness of the plurality of pump lasers.

An optical amplifier is provided in which adjacent ones of a plurality of cores each containing a rare-earth element and included in an amplifying multi-core optical fiber (MCF) serve as coupled cores at an amplifying wavelength, a connecting MCF is connected to the amplifying MCF, a pump light source is connected to the connecting MCF, and the pump light source pumps the rare-earth element in the amplifying MCF through the connecting MCF.

Some embodiments relate to a generation device that includes: a pulsed laser source generating primary photons having at least one wavelength within pulses having time dissymmetry, a forming device(s) controlling the primary photons so as to generate a selective-polarization, focused input beam, and an optical fiber wherein the primary photons induce secondary photons having different wavelengths resulting from a raman conversion cascade and forming a wide-spectrum output beam having substantially constant energy.

High power lasers and high power laser systems that provide high power laser beams having preselected wavelengths and characteristics to optimize or enhance laser beam performance in predetermined environments, conditions and use requirements. In particular, lasers, methods and systems that relate to, among other things, Raman lasers, up conversion lasers, wavelength conversion laser systems, and multi-laser systems that are configured to match and create specific and predetermined wavelengths at specific points along an optical path having varying requirements along that path.