Abstract: High power parallel fiber arrays for the amplification of high peak power pulses are described. Fiber arrays based on individual fiber amplifiers as well as fiber arrays based on multi-core fibers can be implemented. The optical phase between the individual fiber amplifier elements of the fiber array is measured and controlled using a variety of phase detection and compensation techniques. High power fiber array amplifiers can be used for EUV and X-ray generation as well as pumping of parametric amplifiers.

Abstract: According to an embodiment of the disclosure, a system for producing a higher power laser beam is provided. The system includes an optical fiber having a length. The optical fiber is configured to receive inputs from multiple laser pumps and an input from a Stokes seed laser pump. The optical fiber has a core that is doped. The core, when viewed from a cross-section of the optical fiber, has a higher concentration of doping at a location near an axis of the optical fiber than a location further from the axis of the optical fiber. The optical fiber is also configured to convert pump power to Stokes power along the length of the optical fiber when subjected to a Stimulated Raman Scattering (SRS) process.

Abstract: A system for generating a shaped optical pulse is disclosed. The system includes a master oscillator for generating an initial optical pulse, which is then directed to a semiconductor optical amplifier to amplify a portion of the initial optical pulse. The amplified pulse is reflected from a fiber Bragg grating to spectrally clean the amplified pulse and the reflected portion is returned back through the semiconductor optical amplifier. The semiconductor optical amplifier is activated a second time to amplify the reflected portion of the pulse. The time delay between the two activations of the semiconductor optical amplifier is selected to generate an output pulse with desired duration and/or amplitude profile over time.

Abstract: An optical amplifier includes an optical gain fiber into which signal light and pump light are input and at least one relative phase shifter is inserted. Preferably, the relative phase shifter is inserted so that the relative phase in the lengthwise direction of the optical gain fiber falls within a predetermined range containing 0.5?. Preferably, the optical gain fiber is a highly non-linear optical fiber having a non-linearity constant of at least 10/W/km. Preferably, the dispersion of the optical gain fiber is within the range from ?1 ps/nm/km to 1 ps/nm/km in an amplification band. Preferably, the absolute value of the dispersion slope of the optical gain fiber at a zero dispersion wavelength is no greater than 0.05 ps/nm2/km.

Abstract: In one embodiment, an optical system for amplifying space-multiplexed optical signals includes an input fiber that propagates multiple spatially-separated optical signals and a bulk amplifier formed of a doped material that receives the multiple spatially-separated optical signals and simultaneously amplifies those signals to generate multiple amplified signals.

Abstract: A hybrid optical source that provides an optical signal having a wavelength is described. This hybrid optical source comprises an optical amplifier (such as a III-V semiconductor optical amplifier) that is butt-coupled or vertically coupled to a silicon-on-insulator (SOI) platform, and which outputs an optical signal. The SOI platform comprises an optical waveguide that conveys the optical signal. A temperature-compensation element included in the optical waveguide compensates for temperature dependence of the indexes of refraction of the optical amplifier and the optical waveguide. In addition, a reflector, included in or in-line with the optical waveguide and after the temperature-compensation element, reflects a portion of the optical signal and transmits another portion of the optical signal that has the wavelength.

Abstract: Embodiments of the disclosure are directed to optical dark section conditioning. An embodiment generates at least one of a broadband noise or signal at the head end of a section for a first module of the section; and operates all other modules of the section in gain control mode.

Abstract: There is provided an optical amplifier, which includes: an optical amplification medium; a pump light generator configured to generate pump light with a power corresponding to a set control value and supply the generated pump light to the optical amplification medium; a first controller including a level control circuit configured to generate the control value such that an output power of the optical amplification medium approaches a target power, and a limiter configured to limit a range of the control value in variable; and a latch circuit configured to set a specific control value to the pump light generator during a period in which the first controller is in a stop state.

Abstract: A pulse light source device for creating fs output pulses, includes a driver source device including a ps laser pulse source for creating a ps laser pulse output, a first beam splitting device for splitting the ps laser pulse output to first and second ps driver pulses, a first spectral broadening device for creating first fs driver pulses by spectrally broadening the first ps driver pulses, an optical parametric amplifier (OPA) device for creating CEP stabilized second fs driver pulses, and for seeding on the basis of the first fs driver pulses and pumping with the second ps driver pulses, wherein the second fs driver pulses include idler pulses of the OPA device, and a second spectral broadening device for creating the fs output pulses, and arranged to be driven on the basis of the second fs driver pulses. Furthermore, a method of creating fs output pulses is described.

Abstract: An optical pumping apparatus for few-mode fiber amplification is provided. The optical pumping apparatus includes an optical pump source configured to generate an optical pump; an optical power divider configured to divide an optical power of the optical pump from the optical pump source so as to output several optical pumps with uniformly distributed optical power; and a modal multiplexer configured to receive the optical pumps from the optical power divider through a plurality of single-mode fibers, multiplex the received optical pumps, apply a multiplexed optical pump to each mode of a few-mode fiber (FMF) amplifier, and adjust a gain difference among modes, wherein the FMF amplifier obtains a gain by amplifying an optical signal with the optical pump.

Abstract: A method and passive device for the coherent combination of two amplified and/or spectrally broadened optical beams using at least one bidirectional optical component (A1, A2), the device includes an amplitude division ring interferometer having optical splitting and recombining elements disposed so as to receive an incident optical beam (S0) and to split it spatially into a first secondary input beam (H1) and a second secondary input beam (H2), optical guiding elements disposed so as to define an optical path in the form of a ring in the interferometer, the at least one bidirectional optical component being disposed on the optical path of the ring interferometer, the splitting and recombining elements being disposed in such a way as to receive and to recombine spatially, temporally and coherently the first secondary output beam (H1?) and the second secondary output beam (H2?), so as to form a coherent output beam.

Abstract: According to one aspect, the invention relates to an optic fiber amplifier having a high Brillouin threshold, and including: an amplification optic fiber (16) comprising a core and a sheath and suitable for amplifying a signal beam travelling in said core; means for coupling the signal beam in an input end of said amplification optic fiber; means for coupling a pump laser beam for pumping said amplification optic fiber; a structure (330, 340) including a deformable portion around which at least one portion of said amplification optic fiber is wound in the shape of turns, said turns being in contact with a surface of said deformable portion, wherein the friction of said optic fiber on said surface resulting, during the deformation of said deformable portion, in an elongation of said amplification optic fiber according to an elongation profile that varies from one turn to the other.

Abstract: A discrete Raman amplifier comprises a Raman gain fiber, an input port into the Raman gain fiber for receiving optical signals to be Raman amplified, and an output port out of the Raman gain fiber for emitting Raman-amplified optical signals. A pump light input provides pump light to the Raman gain fiber at a plurality of wavelengths so as to provide Raman amplification over the selected signal wavelength range. Within both the pump light wavelength range and the selected signal wavelength range, the Raman gain fiber has only positive chromatic dispersion, and the Raman gain fiber has a moderate effective area.

Abstract: A manufacturing method for an optical semiconductor device, including disposing a semiconductor element that has a polarization dependent gain or polarization dependent loss between optical waveguide modes differing in the direction of polarization, positioning a lens at one end face side of the semiconductor element based on an optical coupling loss between the lens and the semiconductor element, and repositioning the lens based on the polarization dependent gain or the polarization dependent loss of the semiconductor element.

Abstract: The carrier-envelope phase (CEP) of a laser pulse has been shown to influence many physical processes such as pulse propagation through polar molecules, cross-phase modulation, ponderomotive surface-plasmon electron acceleration, photoemission from metallic surfaces, terahertz emission from the laser breakdown of air, above-threshold ionization, high harmonic generation, and attosecond pulse generation. Current technology does not allow for the CEP stabilization of chirped pulse amplification (CPA) systems operating at a repetition rate much lower than a kHz. The inventors disclose apparatus and methods that enable CEP control in CPA systems operating at arbitrarily-low repetition rates.

Abstract: A system for conversion or amplification using quasi-phase matched nonlinear optical wave-mixing comprises a first radiation source for providing a pump radiation beam, a second radiation source for providing a signal radiation beam, and a bent structure for receiving the pump radiation beam and the signal radiation beam. The radiation propagation portion of the bent structure is made of a uniform nonlinear optical material and the radiation propagation portion comprises a dimension taking into account the spatial variation of the nonlinear optical susceptibility along the radiation propagation portion as experienced by radiation travelling along the bent structure for obtaining quasi-phase matched nonlinear optical wave-mixing in the radiation propagation portion. The dimension thereby is substantially inverse proportional with the linear phase mismatch for the nonlinear optical process.

Abstract: A multi-core amplification optical fiber includes a plurality of rare-earth-doped core portions and a cladding portion positioned at an outer periphery of the core portions and having refractive index lower than those of the core portions. When a doping concentration of the rare-earth of each of the core portions is 250 ppm to 2000 ppm, a relative refractive index difference of each of the core portions relative to the cladding portion is 0.5% to 2% at a wavelength of 1550 nm, and a core diameter of each of the core portions is 1 ?m to 5 ?m, a separation distance between each of the core portions and adjacent one of the core portions is set at equal to or larger than 30 ?m and at equal to or smaller than 60 ?m so that a light-crosstalk between the adjacent core portions is equal to or lower than ?30 dB.

Abstract: A solid state detection system includes a degenerate photo-parametric amplifier (PPA), wherein the PPA comprises a photo diode, and a periodically pulsed light source, wherein the photo-parametric, amplifier (PPA) is synchronized to the pulsed light source with a phase locked loop that generates a pump waveform for the PPA at twice the frequency of the excitation pulse rate.

Abstract: Apparatus and method for suppressing modal instabilities (MI) in fiber-amplifier systems. In some embodiments, thermal effects drive the MI process, and in some such embodiments, the present invention provides a plurality of options for mitigating these thermal effects. In some embodiments, the present invention provides a hybrid fiber with a smaller core in the initial length where the thermal loads are highest, followed by a larger-core fiber. In some embodiments the length of the smaller-core section is chosen to keep the core heat-per-unit-length of the second section below a critical value for the onset of MI. In some embodiments, the hybrid fiber of the present invention avoids modal instabilities while yielding almost the same performance as compared to conventional fibers with regard to minimizing fiber nonlinearities such as Stimulated Brillouin Scattering (SBS). In some embodiments, the hybrid fiber outputs a signal beam with at least 1 kW of power.

Abstract: One or more input access waveguides are connected to an optical splitter arranged to divide the light into two or more output waveguides, at least two of the splitter's output access waveguides are used to form a Mach-Zehnder interferometer modulator where at least one arm of the interferometer has a phase modulator electrode and a single electrical contact is arranged to apply a common voltage simultaneously to a selected portion in each arm, or selected portions in each arm of the waveguides that are disposed after the splitter but preceding the phase modulation electrodes, or alternatively the single electrical contact is arranged to apply the voltage to a selected portion of the input access waveguide connected to the splitter and in one or more selected portions of one or both of the arms after the splitter but preceding the phase modulation electrodes to provide gain or reduced optical loss.