Abstract: A device for amplifying a laser beam along an axis comprises: an amplifying bar structure of index nc, delimited by a surface connecting the input and output faces of the structure, having a dimension e along the axis and ? along a perpendicular direction, with e<?, and intended to be pumped to become a gain medium with a maximum along a face, and a liquid of index nA which surrounds the structure in relation to its surface and which is absorbent or scattering at the fluorescence wavelength of the amplifying bar structure. The surface comprises a first tooth in the form of a chamfer at its junction with the maximum gain face, to avoid causing parasitic transverse lasing and the liquid of index nA has a heat capacity of greater than 3000 Joules per kilogram per K° to dissipate the thermal power induced by the pumping.

Abstract: A system and method for high power parametric amplification based on performing amplification in a frequency domain after time domain pulses are optically Fourier transformed, to overcome bandwidth limitations. In a nutshell, a first optical Fourier transformation of a seed spectrum is performed and parametric amplification is carried out in this spatially dispersed frequency plane. As a consequence, individual parts of the spectrum can be amplified using an optical amplification medium comprising a series of optical amplification units, such as different narrowband crystals, placed one next to each other. Each crystal is tuned independently to optimize its corresponding spectral slice. A second optical Fourier transformation recovers the time domain laser pulses. This method enables scalability of amplified bandwidth and pulse energy at the same time.

Abstract: An optical network component is provided comprising a semiconductor optical amplifier with an input and an output, wherein the input is connected to a light source, wherein the output is connected to an amplitude modulator, wherein the semiconductor optical amplifier converts an amplitude modulated signal from the amplitude modulator to a phase modulated signal and provides the phase modulated signal at its output. Also, a transmitter comprising at least one such optical network component is suggested.

Abstract: A method for filtering noises in an optical parametric chirped-pulse amplifier by a spatial-chirp-dressed seed beam is provided. The various noises that grow during amplification course, including parametric super-fluorescence, pump distortion-induced noise and surface-reflection-initiated pre-pulses, will not have the spatial and temporal chirp. After dechirping amplified signal with a compressor, a main pulse having its spatial and temporal chirp removed completely is produced, while the noises acquire an additional spatiotemporal coupling, making themselves highly distinguishable from signal in space, and hence supporting noise filtering effectively and expediently in spatial domain that would not be possible otherwise. The method has capabilities of an order of magnitude reduction in noise energy and several orders of magnitude enhancement in temporal contrast.

Abstract: According to some embodiments a few moded optical fiber includes a glass core structured to provide light amplification at an amplification wavelength and a cladding surrounding the core. According to some embodiments the core of the few moded optical fiber includes a portion that has an average concentration of rare earth dopant which is lower by at least 30%, and preferably by at least 50%, than the average concentration of the rare earth dopant at another portion of the core that is situated further from the core center.

Abstract: Devices and methods for lessening a thermal dependence of gain profile of an optical amplifier are disclosed. An optical beam is split in two sub-beams with a thermally variable power splitting ratio. One sub-beam travels a longer optical path length than the other. When the two sub-beams are recombined, they interfere with each other, causing the throughput to be wavelength dependent. An amplitude of this wavelength dependence is thermally variable due to the thermally variable power splitting ratio. The thermally variable power splitting ratio and the optical path length difference are selected so as to offset a thermal variation of a spectral gain profile of an optical amplifier.

Abstract: A Raman pump may include a dual output laser configured to output two optical signals; a delay interferometer configured to delay a first of the two optical signals to decorrelate the two optical signals from each other; and a combiner configured to combine the delayed first of the two optical signals and a second of the two optical signals to provide a Raman amplification signal.

Abstract: In a Raman system, a primary laser source emits laser light at an initial wavelength, and a seed source emits a multi-wavelength seed laser light. The seed wavelengths correspond to a respective Stokes orders of the primary laser light. The primary laser light and the seed laser light are combined and fed into a Raman gain medium. Stimulated Raman scattering (SRS) causes the primary laser light to be converted into laser light at a selected target wavelength. The seeding of the primary light mediates the conversion process, so as to reduce spontaneous Raman scattering.

Abstract: A high-powered double cladding (DC) pumped Ytterbium-free L-band Erbium doped fiber amplifier (EDFA) for dense-wavelength-division multiplexing (DWDM) is disclosed. The DC pumped Ytterbium-free L-band EDFA comprises a length of DC Erbium-doped fiber (EDF) that has a low-index, large-diameter core. For some embodiments, the DC-EDF also comprises a trench that is located radially exterior to the cladding, thereby increasing cladding absorption while still effectively maintaining single-mode behavior.

Abstract: In one aspect a power amplifier comprises a first plurality of laser disks disposed in a first vertical plane and a second plurality of laser disks disposed in a second vertical plane, opposite the first vertical plane, wherein the plurality of laser disks are disposed in a central horizontal plane, and a first plurality of reflecting mirrors disposed in the first vertical plane and a second plurality of reflecting mirrors disposed in the second vertical plane, wherein a first set of reflecting are disposed in a lower horizontal plane and a second set of reflecting mirrors are disposed in an upper horizontal plane, wherein respective laser disks and reflecting mirrors adjacent along an optical axis are positioned to provide a 1:1 imaging system therebetween. Other aspects may be described.

Abstract: Casing signals generated by an EMAT in a borehole are processed using at least two orthogonal band-limited filters. The band-limited filters may include Gaussian or Cauchy Wavelet filters. By using the Hilbert transform, an envelope of the filtered signals is determined and amplitudes and arrival times of individual arrivals are estimated. These can be used to estimate casing and cement properties.

Abstract: Various embodiments described herein include rare earth doped glass compositions that may be used in optical fiber and rods having large core sizes. Such optical fibers and rods may be employed in fiber lasers and amplifiers. The index of refraction of the glass may be substantially uniform and may be close to that of silica in some embodiments. Possible advantages to such features include reduction of formation of additional waveguides within the core, which becomes increasingly a problem with larger core sizes.

Abstract: A regenerative amplifier according to one aspect of this disclosure is used in combination with a laser device, and the regenerative amplifier may include: a pair of resonator mirrors constituting an optical resonator; a slab amplifier provided between the pair of the resonator mirrors for amplifying a laser beam with a predetermined wavelength outputted from the laser device; and an optical system disposed to configure a multipass optical path along which the laser beam is reciprocated inside the slab amplifier, the optical system transferring an optical image of the laser beam at a first position as an optical image of the laser beam at a second position.

Abstract: An apparatus and method for compensating for mode-profile distortions caused by bending optical fibers having large mode areas. In various embodiments, the invention micro-structures the index of refraction in the core and surrounding areas of the inner cladding from the inner bend radius to the outer bend radius in a manner that compensates for the index changes that are otherwise induced in the index profile by the geometry and/or stresses to the fiber caused by the bending. Some embodiments of an apparatus and method include a fiber having a plurality of substantially parallel cores, the fiber including a straight section and a curved section; guiding signal light primarily in a second core in the straight section; guiding the signal light from the second core into a first core between the straight section and the curved section; and guiding the signal light primarily in the first core in the curved section.

Abstract: 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.

Abstract: The system contains an input fiber section coupled in optical communication with an optical input signal. A length of doped optical gain fiber is optically coupled with the input fiber section. A pumping mechanism is coupled to the doped optical gain fiber. An output port is formed at a distal end of the doped optical gain fiber, wherein the output port is approximately less than twenty centimeters long.

Abstract: A laser device includes: an optical amplifier; a first reflector configured to reflect light output from the first optical end face of the optical amplifier; a ring resonator; an input optical waveguide optically coupled to the ring resonator; a reflector optical waveguide optically coupled to the ring resonator; a second reflector configured to reflect light that propagates in the reflector optical waveguide; an output optical waveguide; and a delay interferometer that includes first and second optical couplers and a pair of optical waveguides formed between the first optical coupler and the second optical coupler. The second optical end face of the optical amplifier and one port of the first optical coupler are optically coupled. A first port of the second optical coupler and the input optical waveguide are optically coupled. A second port of the second optical coupler and the output optical waveguide are optically coupled.

Abstract: Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.

Abstract: Grooves (22, 23) for containing an optical fiber and five recesses (24) for containing the optical components for an optical fiber amplifier are provided in the surface of a substrate (21). An optical fiber fitted in a groove (23a) for containing the optical fiber and introduced to the substrate (21) is passed through a groove (22a) for containing the optical fiber and fitted in a groove (22) for containing the optical fiber, thence passed through a groove (22b) for containing the optical fiber and introduced to the outside of the substrate (21). In the recess (24) for containing the optical component for an optical fiber amplifier, an optical component such as a photocoupler is fitted and coupled with the optical fiber. Light such as pumping light is passed through an optical fiber contained in the groove (23) for containing the optical fiber and introduced to an optical component such as a photocoupler.

Abstract: Stimulating emission via thulium's lasing transition from the 3H4 manifold to the 3H6 manifold yields light at wavelength of about 820 nm. Unfortunately, excited thulium ions also transition from the 3H4 manifold to the long-lived 3F4 manifold, where they become trapped and can no longer participate in the lasing transition. If the enough of the thulium population becomes trapped in the 3F4 manifold, the gain medium becomes transparent at the pump wavelength, rendering population inversion difficult or impossible. Fortunately, the size of the population in the 3F4 manifold can be limited by selecting an appropriate crystal host and thulium doping concentration, pumping the thulium with pulses shorter than the 3F4 manifold's lifetime, cooling the gain medium to low temperature (e.g., 77 K), stimulating emission from the 3F4 manifold, upconversion pumping of the thulium from the 3F4 manifold to the 3H4 manifold, or transferring energy from thulium in the 3F4 manifold to a co-dopant.