Abstract: A Raman amplifier comprising a gain control unit adapted to control a pump power of an optical pump signal in response to at least one monitored optical feedback signal reflected back from a transmission line fiber connected to said pumped Raman amplifier.

Abstract: Systems and methods for reducing cost and amplifier module size are disclosed. One system comprises an arrayed optical fiber amplifier that uses a ribbonized fiber that permits reduction of amplifier module size and also reduction in the cost of manufacturing that are not readily achievable in other currently-available systems.

Abstract: A hybrid optical source includes a substrate with an optical amplifier (such as a III-V semiconductor optical amplifier). The substrate is coupled at an angle (such as an angle between 0 and 90°) to a silicon-on-insulator chip. In particular, the substrate may be optically coupled to the silicon-on-insulator chip by an optical coupler (such as a diffraction grating or a mirror) that efficiently couples (i.e., with low optical loss) an optical signal into a sub-micron silicon-on-insulator optical waveguide. Moreover, the silicon-on-insulator optical waveguide optically couples the light to a reflector to complete the hybrid optical source.

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: Techniques and devices for using a chirped fiber Bragg grating to compress amplified laser pulses.

Abstract: An output characteristic of a monotonic system is controlled using a plurality of adjustable inputs. The adjustments are controlled using a set of setpoints and a set of dither magnitudes. Each input's adjustment is controlled simultaneously using a setpoint and a dither around the setpoint. The dither values for each input have a zero mean and there is zero correlation between the dithers applied to different inputs. The changes in the output characteristic that result from the dithers are measured, and are used to create an adjustment value. The adjustment value is used to create a set of adjusted dither magnitudes. The set of adjusted dither magnitudes are added to a set of integrated prior adjusted dither magnitudes to create a set of setpoint adjustments. Adding the setpoint adjustments to corresponding setpoints creates a set of updated setpoints. This process is repeated so that the setpoints converge on a value that maximizes the output characteristic being controlled.

Abstract: Radiation from a VBG-locked diode-laser at a locked wavelength of 878.6 nm is focused into a 30-mm long Nd:YVO4 optical amplifier crystal for optically pumping the crystal (24). The crystal amplifies a beam of seed-pulses from a fiber MOPA (12). The power of pump radiation is about 75 Watts. The radiation is focused into a beam-waist having a minimum diameter of about 600 micrometers. This provides an amplifier having a high gain-factor well over 100. The high-gain factor provides a gain-shaping effect on the seed-pulse beam which overcomes thermal aberrations inherent in such high-power pumping, thereby producing an amplified seed-pulse beam with M2 less than 1.3.

Abstract: A system for the optical amplification of high-energy ultrashort light pulses, includes: an oscillator that can emit light pulses of sub-picosecond duration ?0, a pre-compensator, and a solid optical amplifier that can amplify the chirped light pulses. The pre-compensator has a negative group velocity dispersion, the pre-compensator being capable of generating negatively chirped light pulses, and the optical amplifier has a positive group velocity dispersion, the optical amplifier being disposed such as to receive and amplify the negatively chirped light pulses. The optical amplifier is configured such that the light pulses can induce a broadening of the spectral gain band ?? by self-phase modulation, such as to generate amplified, time-compressed light pulses of duration ?3, which is shorter than the duration ?=1/?? of the bandwidth limitation of the optical amplifier.

Abstract: A planar optical waveguide amplifier includes an active optical waveguide (203) containing rare-earth ions embedded in a passive optical waveguide (202) that guides the pump power.

Abstract: An optical amplification device includes: a port group that has a plurality of ports that have a semiconductor optical amplifier and a port that does not have a semiconductor optical amplifier, an optical burst signal being input into each of the ports at a different timing; and a control unit, wherein: when an optical inputting into the port that has the semiconductor optical amplifier is detected, the control unit activates the semiconductor optical amplifier of the port where the optical inputting is detected, inactivates the other semiconductor optical amplifier and remains an activation until another optical inputting is detected in another semiconductor optical amplifier; and when an optical inputting into the port that does not have the semiconductor optical amplifier is detected, the control unit inactivates the semiconductor optical amplifiers of the plurality of the ports that have the semiconductor optical amplifier.

Abstract: A pulsed fiber laser amplifier system including a plurality of optical seed beam sources each generating a seed pulse beam at a different point in time and at a different wavelength than the other seed beam sources. The system further includes an optical coupler responsive to each of the seed pulse beams that outputs the pulse beams on a common optical path as a pulsed envelope beam. The system also includes a plurality of fiber amplifier stages responsive to the pulse envelope beam from the optical coupler that amplifies each pulse in the pulse envelope beam. The system further includes a spectral-temporal beam combiner that provides a separate delay for each of the amplified pulses in the pulse envelope beam so as to output a single output beam pulse that is in overlap of all of the individual amplified pulses in the pulse envelope beam.

Abstract: An amplifying apparatus includes an optical fiber that includes a wound portion doped with a rare earth element and three-dimensionally wound, holes being formed in cladding of the optical fiber and surrounding a core of the optical fiber, the optical fiber transmitting signal light injected thereinto; a thermally conductive member in which the wound portion of the optical fiber embedded, the thermally conductive member having thermal conductivity; a light source that emits excitation light; an injecting unit that injects the excitation light emitted by the light source, into the optical fiber; and a temperature adjusting unit that includes a thermal coupling unit thermally connected to the light source and the thermally conductive member, the temperature adjusting unit adjusting a temperature of the thermal coupling unit.

Abstract: An optical fiber propagates a light beam at a predetermined wavelength at least in an LP01 mode and an LP02 mode. A dopant that changes a Young's modulus is doped to at least a part of a waveguide region 12a of a cladding 12 through which a light beam at a predetermined wavelength is propagated and to a region 11b in a core 11 in which the intensity of the light beam in the LP01 mode is greater than the intensity of the light beam in the LP02 mode. At least a part of the Young's modulus in the waveguide region 12a of the cladding 12 is smaller than a Young's modulus in the region 11b in the core 11 in which the intensity of the light beam in the LP01 mode is greater than the intensity of the light beam in the LP02 mode.

Abstract: A technique is described for providing compensation for the thermo-optic effect in a large-mode-area optical fiber, filter fiber, or the like. An optical fiber is provided having a refractive index profile with ambient temperature loss characteristics including a low loss for a first type of light and a high loss for a second type of light. A hot region of the fiber connected into an optical system is identified, in which a thermal index gradient is induced in the fiber. The thermal index gradient, in the absence of a compensating index gradient, would result in degradation of the fiber's ambient temperature loss characteristics. The fiber is arranged according to a layout having a position-varying bending diameter. Throughout the identified hot region, the fiber has a compensating bending diameter that induces a compensating index gradient in the fiber.

Abstract: A tunable transmission optical filter is optically coupled between a laser section and semiconductor optical amplifier (SOA) section of a tunable laser device. The optical filter may be tuned to provide a high transmission near the lasing peak while suppressing a significant portion of back-propagating amplified spontaneous emission (ASE) of the SOA section. Without the optical filter, the laser output spectrum may develop side lobes of higher intensity after the ASE is amplified and reflected in the forward direction by the laser gain and mirror sections. While lessening the side lobes, the optical filter simultaneously transmits the laser peak for amplification by the SOA section.

Abstract: An optical amplification component 1 includes a heat dissipation plate 10 and an amplification optical fiber 20 arranged on the heat dissipation plate 10. The amplification optical fiber 20 includes a first section SC1 extending from a reference position RP between a first end E1 and a second end E2 of the amplification optical fiber 20 up to a position at which a fiber portion 20A extending from the reference position RP toward the end E1 and a fiber portion 20B extending from the reference position RP toward the end E2 are aligned in one direction, and a second section SC2 where the fiber portions 20A and 20B aligned in one direction are wound in a spiral outside the first section SC1. The circumferences of one and the other end parts of the amplification optical fiber 20 are separated from side surfaces of the fiber portions wound in a spiral.

Abstract: An optical branching device includes: a Faraday rotator capable of controlling polarized wave of input light based on a change of a magnetic flux density depending on a magnetic field to be provided; a magnet configured to provide the Faraday rotator with the magnetic field; a polarization beam splitter configured to branch, by a polarized wave component, the input light which passes through the Faraday rotator; a bimetal configured to deform depending on a temperature; and a controller configured to have a mechanism to use force accompanying with the deformation of the bimetal so as to control a relative positional relationship between the Faraday rotator and the magnet.

Abstract: Wavelength-selective external resonators can be used to greatly increase the output brightness of dense wavelength beam combining (DWBC) system beams by stabilizing the wavelengths of the beams emitted by the individual emitters of the DWBC laser source. The present invention pertains to external resonant cavities that utilize thin-film filtering elements as wavelength-selective elements in external resonators. The present invention further pertains to particular embodiments that utilize thin-film filtering elements in DWBC systems as both output beam coupling elements and wavelength selective elements. The present invention provides advantages over the prior art that include decreased cost, increased fidelity of wavelength selection, and increased wall plug efficiency.

Abstract: Techniques are presented herein to set power levels for multiple Raman pump wavelengths in a distributed Raman amplification configuration. A first receive power measurement is obtained at a second node with a controlled optical source at a first node turned on and with a plurality of Raman pump lasers at different wavelengths at the second node turned off. A second receive power measurement is obtained at the second node with the controlled optical source at the first node turned on and the plurality of Raman pump lasers turned on to respective reference power levels to inject optical Raman pump power at a corresponding plurality of wavelengths into the optical fiber span. Based on a target Raman gain and a target Raman gain tilt, respective ratios of a total power are obtained, each ratio to be used for a corresponding one of the plurality of Raman pump lasers.

Abstract: A pulsed fiber laser apparatus for outputting picosecond laser pulses can comprise a fiber delivered pulsed seed laser for providing picosecond optical seed pulses, and at least one optical fiber amplifier in optical communication with the fiber delivered pulsed seed laser. The optical fiber amplifier can comprise a gain optical fiber that receives and optically amplifies picosecond optical pulses by operating in a nonlinear regime wherein the picosecond optical pulses can be spectrally broadened by a factor of at least 8 during amplification thereof. The apparatus can further comprise a pulse compressor apparatus in optical communication with the optical fiber amplifier for providing compressed picosecond optical pulses.