High-power, highly efficient 3-level system fiber lasers are described. The lasers can operate at an average power of about 50W or greater with an efficiency of about 60% or greater with low diffraction limited mode quality. The lasers incorporate an all-solid photonic bandgap fiber that includes a large core (20 micrometers or greater), a high core/clad ratio (greater than 15%), and a waveguide cladding designed to define a transmission band to suppress the 4-level system of the gain medium through determination of the node size of individual nodes of a cladding lattice.

A Raman fiber laser source (RFLS) is configured with a feeding fiber delivering MM pump radiation to an inner cladding of double-clad MM Raman fiber laser. The MM pump radiation has a sufficient power to produce Raman scattering in the MM Raman fiber converting the pump radiation to a MM signal radiation at a Raman-shifted wavelength ram which is longer than a wavelength pump of the pump radiation. The RFLS further has a pair of spaced reflectors defining therebetween a resonator for the signal radiation at a 1.sup.st Stokes wavelength and flanking at least part of the MM core of the Raman fiber which is provided with a central core region which is doped with impurities for enhancing Raman process. The reflectors and central core region are dimensioned to correspond to the fundamental mode of the MM signal radiation.

The present disclosure relates to a glass having a refractive index of at least 1.7 as well as the use of the glass as a cladding glass of a solid-state laser. The disclosure also relates to a laser component comprising a core of doped sapphire and a cladding glass being placed on said core. The cladding glass is arranged on said core such that light exiting from the core due to parasitic laser activity can enter the cladding glass and can be absorbed there. Thus, a laser component with improved efficiency is obtained. The present disclosure also relates to a method for producing the laser component.

Coupled resonators having two resonances are described. A first resonance occurs at the frequency of a pump signal. A second resonance occurs at the frequency of a first Stokes signal. The stop band of the coupled resonators suppresses the second Stokes signal and thus all other higher order Stokes signals. The coupled resonators can be used to more efficiently generate a first Stokes signal having a narrow line width signal.

A method of emitting photons at a desired wavelength, including: providing a material having a first region of high absorption of radiation at a first set of wavelength of radiation, contiguous with a second region of low absorption of radiation at a shorter set of wavelengths, and a third region of high emission at a further shorter set of wavelengths; applying energy to the material at the first region, such that most of an effective black body radiation of said material at a temperature of the material would fall within the second region and be configured to transfer energy to said third region and not overlap with the first region; and emitting energy from the material at the third region, powered by said applying energy.

A first fiber is connected to a first end of a third fiber doped with a rare earth element, and a second fiber is connected to a second end of the third fiber. In the third fiber doped with the rare earth element, a central portion of a core is more heavily doped with the rare earth element than a peripheral portion of the core is.

An optical fiber includes: an optical waveguide; and a resin coating that is lower in refractive index than the optical waveguide and covers a side surface of the optical waveguide except in a coating-removed section of the side surface. The coating-removed section of the side surface is covered throughout with an inorganic layer that is lower in refractive index than the optical waveguide.

A photonic molecule laser is described that includes a photonic molecule waveguide coupled to a photonic molecule seeding source configured to deliver a plurality of photonic molecules. The photonic molecule waveguide includes a second dopant maintained at a population inverted state with an energy level transition corresponding to a second frequency that is an N-fold multiple of a first frequency and amplifies the number of photonic molecules via stimulated emission. The photonic molecule seeding source includes a waveguide with a first dopant maintained at a population inverted state with an energy level transition corresponding to the first frequency. A pump source is coupled to the waveguide configured to deliver a first frequency laser pulse with pulse coherence time less than the photonic molecules correlation time. Each photonic molecule includes a threshold bound state of N first frequency photons, and each photonic molecule has the second frequency.

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.

A solid state ring laser gyroscope comprises a laser block including a resonant ring cavity having an optical closed loop pathway; a plurality of mirror structures mounted on the block and including respective multilayer mirrors that reflect light beams around the closed loop pathway; and a pump laser assembly in optical communication with the closed loop pathway through one of the mirror structures. One or more of the multilayer mirrors includes a rare-earth doped gain layer operative to produce bidirectional optical amplification of counter-propagating light beams in the closed loop pathway. In some embodiments, the gain layer comprises a rare-earth dopant other than neodymium that is doped into a glassy host material comprising titania, tantalum oxide, alumina, zirconia, silicate glass, phosphate glass, tellurite glass, fluorosilicate glass, or non-oxide glass. Alternatively, the gain layer can comprise a neodymium dopant that is doped into a glassy host material other than silica.