Abstract: An optical fiber comprises a core having an elliptical cross section and a cladding having a circular cross section. The core has an aspect ratio between 2 and 40. The core and the cladding have a common central axis with the core being enclosed by the cladding. The difference of a refractive index of the cladding to a refractive index of the core is between 1×10?2 and 1.5×10?1. A trench is located between the core and the cladding. The trench has a uniform width and encircles the core. The refractive index of the trench is lower than the refractive index of the cladding.

Abstract: A pumping light source outputs pumping lights. A pumping light source outputs a pumping light. Optical multiplexers couple the pumping lights to a plurality of cores. The optical multiplexer couples the pumping light to the clad. A pumping light source drive unit drives a pumping light source. A pumping light source drive unit drives a pumping light source. A monitoring unit outputs a monitoring signal indicating a monitoring result of the number of wavelengths used in each of optical signals amplified by the plurality of the cores. The control unit controls the power of the pumping lights based on the monitoring signal. The control unit controls the power of each of the pumping lights in accordance with the number of wavelengths used in each of the optical signals and controls the power of the pumping light so that signal qualities of the optical signals fall within a prescribed range.

Abstract: The optical fiber of the present invention includes a core, and a cladding that is provided on an outer periphery of the core and has a refractive index lower than a refractive index of the core region. In the optical fiber of the present invention, a V value representing a normalized frequency of an LP02 mode is greater than or equal to 4.8 and less than or equal to 6.4.

Abstract: Provided are radiopaque compositions comprising one or more of yttrium (Y), strontium (Sr), gallium (Ga), and silicon, or oxides and salts thereof. The composition can comprise a combination of Y2O3, SrO, Ga2O3, and SiO2, and optionally MnO2, and TiO2. Other compositions comprise SrO, Ga2O3, TiO2, MnO2, and SiO2. The composition can be a particulate material. The compositions are useful for radioembolization to treat tumors.

Abstract: The optical relay is a C+L-band relay which is inserted between a first transmission path fiber and a second transmission path fiber, and comprises: a first optical fiber amplification unit which is inserted in a first line and amplifies one of a C-band signal or an L-band signal; a second optical fiber amplification unit which is inserted in a second line and amplifies one of the C-band signal or the L-band signal; and an inserting means which inserts some or all of the wavelengths of light output from the first optical fiber amplification unit into the second optical fiber amplification unit, or which inserts some or all of the wavelengths of light output from the second optical fiber amplification unit into the first optical fiber amplification unit.

Abstract: The specification and drawings present a new apparatus such as a lighting apparatus, the apparatus comprising at least one LED (or OLED) module, configured to generate a visible light such as white light, and at least one component such as optical component comprising a compound consisting essentially of the elements neodymium (Nd) and fluorine (F), and optionally including one or more other elements. The lighting apparatus is configured to provide a desired light spectrum by filtering the generated visible light using the compound.

Abstract: Materials and optical components formed thereof that are suitable for use in a lighting apparatus to impart a color filtering effect to visible light. At least a portion of such an optical component is formed of a composite material comprising a polymeric matrix material and an inorganic particulate material that contributes a color filtering effect to visible light passing through the composite material, and the particulate material comprises a neodymium compound containing Nd3+ ions.

Abstract: An optical communication amplification system may include a number of amplification stages for an optical signal that includes a first optical wavelength band signal portion and a second optical wavelength band signal portion. Each amplification stage may separate the first optical wavelength band signal portion from the second optical wavelength band signal portion. The separated first optical wavelength band signal portion is amplified using one or more first optical wavelength band amplifiers and the separated second optical wavelength band signal portion are amplified using one or more second optical wavelength band amplifiers. The amplified first optical wavelength band signal portion is filtered and a reflected portion of the first optical wavelength band signal portion may be used to provide energy to the one or more second optical wavelength band amplifiers to increase the power or gain of the separated second optical wavelength band signal portion.

Abstract: The invention relates to an optical pumping device comprising: a fibre light source emitting controlled radiation having a very high transverse modal quality, with a wavelength shorter than 1000 nm; at least one element consisting of an amplifying material doped with a rare earth dopant; means for introducing a pumping light into said doped amplifying material element; and means for cooling said amplifying material. Said optical pumping device is characterised in that the pumping light is emitted by the fibre light source with an average power of higher than 2W and a modal quality characterised by an M2<5 factor.

Abstract: Provided are an optical amplifier, a light reception element, and a controller configured to decrease a gain of the optical amplifier according to an optical signal power input to the optical amplifier in response to a detection of a recovery of the optical signal input to the optical amplifier from an interruption of the optical signal and to increase the gain of the optical amplifier so that an input optical power to the light reception element approaches a target value after the decreasing of the gain.

Abstract: A few-mode rare-earth-doped amplifier fiber has equalized gain for the supported signal transmission modes. The fiber has a raised-index core surrounded by a lower-index cladding region. The core has a radius a1 and an index difference ?n1 relative to the surrounding cladding region and is configured to support, at a selected signal wavelength, a set of lower-order fiber modes having an optical field with a diameter greater than 2·a1. The fiber further includes an active region, doped with a rare-earth dopant, comprising an inner portion that is coextensive with the core and an outer portion that surrounds the inner portion and extends into the cladding. The active region has an outer radius a2 greater than a1 that encompasses the optical field of the set of lower-order fiber modes at the selected signal wavelength.

Abstract: An ytterbium-doped optical fiber includes: a core which contains at least ytterbium, aluminum, and phosphorus; and a cladding which encircles the core, wherein an aluminum oxide equivalent concentration of the aluminum in the core is 0.2 mol % or more, a diphosphorus pentaoxide equivalent concentration of the phosphorus is higher than the aluminum oxide equivalent concentration, and the core either does not contain germanium or contains less than 1.1 mol % of germanium in a germanium dioxide equivalent concentration.

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: A very large more area active double clad optical waveguide doped with Nd3+ at a concentration of at least 0.1% by weight can be used to effectively amplify light at a wavelength of between 1050 nm and 1120 nm. At a doping concentration sufficient to provide a net optical absorption of at least 3 dB/m for the pump light at the wavelength of 795 to 815 nm or 883 to 887 nm, Nd3+ operates under much lower inversion levels than Yb3+. Due to the lower inversion levels, the Nd3+ doped waveguide is subject to reduced pump bleaching or photodarkening.

Abstract: The invention can include an apparatus for producing optical pulses, comprising an oscillator for producing optical pulses at a first optical pulse repetition frequency, the optical pulses having a first frequency of light; a pulse picker for receiving optical pulses having the first optical pulse repetition frequency and operable to reduce the optical pulse repetition frequency to produce optical pulses having the first frequency and a reduced optical pulse repetition frequency that is less than the first optical pulse repetition frequency; an optical fiber receiving optical pulses having the reduced optical pulse repetition frequency and first frequency, to nonlinearly produce light that includes a frequency that is twice the first frequency; and an Ytterbium doped fiber amplifier in optical communication with the pulse picker and the optical fiber and located between the pulse picker and the oscillator.

Abstract: Various embodiments described herein comprise a laser and/or an amplifier system including a doped gain fiber having ytterbium ions in a phosphosilicate glass. Various embodiments described herein increase pump absorption to at least about 1000 dB/m-9000 dB/m. The use of these gain fibers provide for increased peak-powers and/or pulse energies. The various embodiments of the doped gain fiber having ytterbium ions in a phosphosilicate glass exhibit reduced photo-darkening levels compared to photo-darkening levels obtainable with equivalent doping levels of an ytterbium doped silica fiber.

Abstract: The invention provides an amplification module for an optical printed circuit board, the optical printed circuit board including plural polymer waveguide sections from independent waveguides, each of the sections being doped with an amplifying dopant, wherein the plural waveguide sections are routed so as to pass through an amplification zone in which the plural polymer waveguide sections are arranged close or adjacent to one another, the amplification module including: a pump source including plural light sources arranged to provide independently controllable levels of pump radiation to each of the plural waveguide sections. In an embodiment, the amplification module also includes plural polymer waveguide sections corresponding to the plural polymer waveguides of the printed circuit board on which in use the amplification module is to be arranged, each of the sections being doped with an amplifying dopant.

Abstract: It is disclosed a method for driving a laser diode such as to enable mitigation or elimination of so called spiking effects related to the number of injected carriers in the laser overshooting the equilibrium value at the beginning of the lasing process. In this manner, among other things, the efficiency of a master oscillator power amplifier that may be utilized in range finding applications will be improved. It is further disclosed an optical pulse transmitter comprising such a laser diode.

Abstract: According to some embodiments the optical fiber comprises: (i) a glass core doped with greater than 300 ppm of Er2O3 and at least 0.5 wt % of Al2O3, with a radius R1 from about 3 ?m to about 15 ?m, a relative refractive index delta ?1 from about between 0.3% to 2% relative to the glass cladding; an effective area of LP01 mode between 20 ?m2 and 250 ?m2 at 1550 nm, the glass core radius R1 and refractive index are selected such that the core is capable of supporting the propagation and transmission of an optical signal with X number of LP modes at a wavelength of 1550 nm, wherein X is an integer greater than 1 and not greater than 20; and (ii) a glass cladding surrounding and in direct contact with the glass core.

Abstract: A method of operating a fiber amplifier characterized by a spectral gain curve includes providing an input signal at a signal wavelength. The signal wavelength lies within an in-band portion of the spectral gain curve extending from a first in-band wavelength to a second in-band wavelength, the in-band portion being characterized by a first amplitude range. The method also includes providing pump radiation at a pump wavelength. The pump wavelength is less than the signal wavelength. The method further includes coupling the pump radiation to the fiber amplifier and amplifying the input signal to generate an output signal. All portions of the spectral gain curve at wavelengths less than the first in-band wavelength and greater than the pump wavelength are characterized by a second amplitude less than or equal to 10 dB greater than the first amplitude range.

Abstract: In the method for processing a signal light from free-space by amplifying said signal for free-space optical communications, wherein the improvement includes the steps of (a) pre-amplifying said signal light with low noise; and (b) coupling said signal light into a multimode filter which reduces coupling losses compared to single mode filters.

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 master oscillator power amplifier (MOPA) system includes an oscillator having a neodymium-doped gadolinium vanadate gain-medium and delivering seed-pulses. A length of single mode fiber is used to broaden the spectrum of the seed pulse. An amplifier having a neodymium-doped yttrium vanadate gain-medium amplifies the spectrally broadened seed-pulses. The gain-spectrum of the amplifier partially overlaps the broadened pulse-spectrum, providing spectral selection of the seed-pulses in addition to amplification. This provides amplified output-pulses having a duration about one-third that of the corresponding seed-pulses.

Abstract: An optical amplifier for use as a final amplification stage for a fiber-MOPA has a gain-element including a thin wafer or chip of ytterbium-doped YAG. An elongated gain-region is formed in gain-element by multiple incidences of radiation from a diode-laser bar.

Abstract: The present invention discloses a multi-wavelength light source apparatus. The multi-wavelength light source apparatus includes: a pump light source, configured to provide pump light; an erbium-doped optical fiber, configured to absorb energy of the pump light and emit wide-spectrum laser light; and an optical fiber, configured to filter the wide-spectrum laser light and output a multi-wavelength optical signal in a free spectral range of the optical filter, where the multi-wavelength optical signal is incident on the erbium-doped optical fiber, and the erbium-doped optical fiber is further configured to re-amplify and output the incident multi-wavelength optical signal. In the multi-wavelength light source apparatus in the embodiments of the present invention, a wavelength of output light can be selected, spectral energy of the output light is concentrated, and power of the output light is high.

Abstract: A double-clad (DC) multicore (MC) Erbium-doped fiber amplifier (EDFA) for dense-wavelength-division multiplexing (DWDM) is disclosed. The DC-MC-EDFA comprises a length of DC-MC Erbium-doped fiber (EDF) that is core-matched spliced to a MC tapered signal-pump fiber combiner (TFC). For some embodiments, the optical signals are coupled into the DC-MC-EDF by the MC-TFC, and the pump energy is also coupled into the DC-MC-EDF by the MC-TFC. For some embodiments, the optical signals are also transmitted out of the DC-MC-EDF through the MC-TFC.

Abstract: Systems and methods of high efficiency amplification of pulsed laser output for high energy ultra-short pulse laser systems are provided herein. According to some embodiments, methods for amplifying pulsed laser output for high energy ultra-short pulse laser systems include receiving pulsed laser output and amplifying the pulsed laser output by propagating the pulsed laser output through a non-silica based gain medium that has been doped with a concentration of rare earth ions, wherein the concentration of the rare earth ions within the gain medium is approximately greater than one percent by weight.

Abstract: A method for making a rare earth doped polycrystalline ceramic laser gain medium by hot pressing a rare earth doped polycrystalline powder where the doping concentration is greater than 2% and up to 10% and where the grain size of the final ceramic is greater than 2 ?m. The polycrystalline powder can be Lu2O3, Y2O3, or Sc2O3, and the rare earth dopant can be Yb3+, Er3+, Tm3+, or Ho3+. Also disclosed is the related rare earth doped polycrystalline ceramic laser gain medium prepared by this method.

Abstract: The present invention embraces an amplifying optical fiber having a central core adapted to convey and amplify an optical signal and a cladding that surrounds the central core to confine the optical signal conveyed in the central core. The central core is formed of a core matrix in which nanoparticles are present. The nanoparticles themselves include a nanoparticle matrix and rare-earth-dopant elements. The core matrix may also include one or more additional dopants (i.e., in addition to nanoparticles). The amplifying optical fiber possesses a small numerical aperture and is suitable for use in high-pump-power applications without a degraded gain shape.

Abstract: A rare earth doped optical fiber amplifier is configured to have an enlarged core region and a trench formed adjacent to the core, where at least an inner portion of the trench is also formed to include a rare earth dopant. The presence of the rare earth dopant in the inner region of the cladding minimizes transient power fluctuations within the amplifier as the number of optical signals being amplified changes. The addition of rare earth dopant to the cladding increases the overlap between the pump, signal and the rare earth ions and thus improves the gain efficiency for the optical signal. The relatively large core diameter increases the saturation power level of the rare earth dopant and decreases the transients present in the gain as the input signal power fluctuates.

Abstract: A method of operating a fiber amplifier characterized by a spectral gain curve includes providing an input signal at a signal wavelength. The signal wavelength lies within an in-band portion of the spectral gain curve extending from a first in-band wavelength to a second in-band wavelength, the in-band portion being characterized by a first amplitude range. The method also includes providing pump radiation at a pump wavelength. The pump wavelength is less than the signal wavelength. The method further includes coupling the pump radiation to the fiber amplifier and amplifying the input signal to generate an output signal. All portions of the spectral gain curve at wavelengths less than the first in-band wavelength and greater than the pump wavelength are characterized by a second amplitude less than or equal to 10 dB greater than the first amplitude range.

Abstract: The present invention relates generally to devices for the generation and amplification of electromagnetic energy. The present invention relates more particularly to optical fiber devices, such as lasers and amplifiers, useful for generating and amplifying optical energy.

Abstract: Various embodiments described herein comprise a laser and/or an amplifier system including a doped gain fiber having ytterbium ions in a phosphosilicate glass. Various embodiments described herein increase pump absorption to at least about 1000 dB/m-9000 dB/m. The use of these gain fibers provide for increased peak-powers and/or pulse energies. The various embodiments of the doped gain fiber having ytterbium ions in a phosphosilicate glass exhibit reduced photo-darkening levels compared to photo-darkening levels obtainable with equivalent doping levels of an ytterbium doped silica fiber.

Abstract: An amplifying optical fiber includes a core containing oxides of elements selected from the group consisting of silicon, germanium, phosphorus, bismuth, aluminum, gallium with a concentration of bismuth oxide of 10-4-5 mol %, a total concentration of silicon and germanium oxides of 70-99.8999 mol %, a total concentration of aluminum and gallium oxides of 0.1-20 mol % wherein both aluminum and gallium oxide are present and a ratio of aluminum oxide to gallium oxide is at least two, and a concentration of phosphorus oxide from 0 to 10 mol %, and provides a maximum optical gain at least 10 times greater than the nonresonant loss factor in the optical fiber. An outside oxide glass cladding comprises fused silica. The core has an absorption band in the 1000 nm region, pumping to which region provides an increased efficiency of power conversion of pump light into luminescence light in the 1000-1700 nm range.

Abstract: Disclosed is a stimulated Raman scattering effect (SRS), amplifying optical fiber that includes a central core comprising a dielectric matrix that is capable of vibrating at a given frequency (?Raman) under the effect of a pump signal. The optical fiber includes at least one kind of metallic nanostructure that is capable of generating surface plasmon resonance (SPR) in the optical fiber. The metallic nanostructures have a shape and composition such that the frequency of their surface plasmon resonance (?plasmon) corresponds to the frequency of the pump signal (?pump) and/or the frequency of the optical signal transmitted in the optical fiber (?signal).

Abstract: Various embodiments described herein comprise a laser and/or an amplifier system including a doped gain fiber having ytterbium ions in a phosphosilicate glass. Various embodiments described herein increase pump absorption to at least about 1000 dB/m-9000 dB/m. The use of these gain fibers provide for increased peak-powers and/or pulse energies. The various embodiments of the doped gain fiber having ytterbium ions in a phosphosilicate glass exhibit reduced photo-darkening levels compared to photo-darkening levels obtainable with equivalent doping levels of an ytterbium doped silica fiber.

Abstract: Disclosed is an optical fiber that includes a central core that is suitable for transmitting and amplifying an optical signal and an inner optical cladding that is suitable for confining the optical signal transmitted within the central core. The central core is formed from a core matrix that contains silica-based nanoparticles doped with at least one rare earth element. The disclosed optical fiber can be used with limited optical losses even in an environment with strong ionizing radiation.

Abstract: An amplifier optical fiber comprising a central core of a dielectric matrix doped with at least one element ensuring the amplification of an optical signal transmitted in the fiber and a cladding surrounding the central core and suitable for confining the optical signal transmitted in the core. The fiber also comprises metallic nanostructures suitable for generating an electronic surface resonance in the dielectric matrix of central core, the wavelength of said electronic surface resonance corresponding to an excitation level of the element ensuring the amplification.

Abstract: An optical source configured for providing output light for providing input signal light or pump light can comprise pump source for pumping a four wave mixing (FWM) process with light pulses (“FWM pump light”); a FWM element in optical communication with the pump source, the FWM element configured for hosting the FWM process to generate, responsive to the FWM pump light, pulses of FWM signal light and FWM idler light having different wavelengths. The optical source can be configured such that the output light comprises pump light having a pumping wavelength or as input signal light having a gain wavelength for pumping or seeding an amplifying optical device comprising a gain material for providing optical gain. The gain material can have absorption and emission spectra defining gain and pumping wavelengths at which, respectively, the gain material is arranged in the device to provide optical gain via a process of stimulated emission responsive to being pumped.

Abstract: An ytterbium-doped optical fiber of the present invention includes: a core which contains ytterbium, aluminum, and phosphorus and does not contain germanium; and a cladding which surrounds this core. The ytterbium concentration in the core in terms of ytterbium oxide is 0.09 to 0.68 mole percent. The molar ratio between the phosphorus concentration in the core in terms of diphosphorus pentoxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 30. The molar ratio between the aluminum concentration in the core in terms of aluminum oxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 32. The molar ratio between the above aluminum concentration in terms of aluminum oxide and the above phosphorus concentration in terms of diphosphorus pentoxide is 1 to 2.5.

Abstract: A system for combining multiple fiber amplifiers, or multiple fiber amplifiers. The system includes a fiber combiner with multiple cores for connecting with the multiple fiber amplifiers and for combining the beams of the fiber amplifiers into a single beam. The fiber amplifiers are aligned, tapered, and stretched. A method for combining fiber amplifiers includes emitting a beam from a tapered fiber combiner and transmitting and coupling a portion of the emitted beam back into the fiber combiner via a feedback fiber. The transmission and coupling of the feedback fiber includes mixing the feedback fiber with the output of an auxiliary laser and boosting the feedback fiber by a pre-amplifier. The feedback fiber is split into a plurality of beams by a fiber splitter. The beams are fed into an array of fiber amplifiers and combined with output of the individual fiber amplifiers to form the tapered fiber combiner.

Abstract: A light-emitting apparatus composed of a light source that emits primary light and a phosphor that absorbs the primary light and emits secondary light offers high brightness, low power consumption, and a long lifetime while minimizing adverse effects on the environment. The phosphor is formed of a III-V group semiconductor in the form of fine-particle crystals each having a volume of 2 800 nm3 or less. The light emitted from the fine-particle crystals depends on their volume, and therefore giving the fine-particle crystals a predetermined volume distribution makes it possible to adjust the wavelength range of the secondary light.

Abstract: Embodiments of the present invention disclose a method, an apparatus, and a system for amplifying a burst optical signal. The method includes: monitoring an input status of a signal light; when no signal light is input, controlling output power of a pump light so that a gain medium has output optical power and the output optical power is less than a maximum optical power that the gain medium is capable of outputting when a signal light is input; inputting the pump light into a wavelength division multiplexer so that the wavelength division multiplexer combines the signal light and the pump light and inputs the combined light into the gain medium. With the preceding manners, when no signal light is input, the power of the pump light is controlled.

Abstract: The pulse light source according to the present invention comprises: a seed pulse generator 1 for outputting an input pulse 10 as a seed pulse; a pulse amplifier 2; and a dispersion compensator 3 for dispersion compensating a light pulse output from the pulse amplifier 2. Moreover, the pulse amplifier 2 comprises a normal dispersion medium (DCF 4) and an amplification medium (EDF 5) that are multistage-connected alternately, for changing the input pulse 10 to a light pulse having a linear chirp and outputting the light pulse. Furthermore, an absolute value of the dispersion of the DCF 4 becomes to be larger than the absolute value of the dispersion of the EDF 5.

Abstract: An amplifying optical fiber includes an inner core, an inner cladding, a depressed trench, and an outer cladding (e.g., an outer optical cladding). Typically, the inner core includes a main matrix (e.g., silica-based) doped with at least one rare earth element. The depressed trench typically has a volume integral V13 of between about ?2200×10?3 ?m2 and ?1600×10?3 ?m2. Exemplary embodiments of the amplifying optical fiber are suitable for use in a compact configuration and high power applications.

Abstract: An apparatus and method for receiving electromagnetic waves using photonics includes a transmission unit transmitting electromagnetic waves in intervals; a time delay unit coupled to the transmission unit and controlling the transmission unit to transmit the electromagnetic waves in the intervals; an antenna receiving the electromagnetic waves reflected from the target; an interferoceiver coupled to the antenna and receiving the electromagnetic waves from the antenna, the interferoceiver comprising an optical recirculation loop to produce replica electromagnetic waves; and a computer identifying the target from the reflected electromagnetic waves.

Abstract: Disclosed is an optical amplifier which includes an upward optical amplifier configured to amplify an input upward optical signal of an input optical signal; and a control circuit configured to control an operation of the upward optical amplifier according to whether an upward stream is detected from the input upward optical signal.

Abstract: An all fiber mid-IR pulse generator is disclosed that may be used to drive an external non-linear converter. The generator comprises fiber laser oscillator and fiber amplifier elements wherein diode lasers are used to cladding pump the different fiber elements depending on different configurations of the pulse generator. Gain switching of the fiber lasers precludes the need for discrete devices such as Q-switches to generate pulses. The fiber laser and fiber amplifier elements are all fused together, along with fiber isolators and reflective gratings, so there is no free space coupling, and there are no optical elements except as may be needed to couple the output of the generator to a non-linear converter. The all fiber implementation has a single transverse mode at the lowest order mode of operation which results in a nearly diffraction limited output which causes non-linear converters to operate more efficiently.

Abstract: A chirped-pulse fiber amplification method and system operates with large nonlinear phase shifts (as large as ˜20? or more). In this regime, the pulse spectrum is modified by strong self-phase modulation and gain shaping. With large-enough nonlinear phase shift, substantial spectral broadening occurs. The amplified spectrum can therefore be much broader than the spectrum that is obtained with small nonlinear phase shifts. The broader spectrum enables the formation of a shorter pulse, and the bandwidth generated in nonlinear chirped-pulse amplification can in fact be exploited to generate shorter pulses. Ultimately, this allows the generation of pulses shorter than the gain-narrowing limit of a fiber amplifier.

Abstract: Embodiments described herein include a system for producing ultrashort tunable pulses based on ultra broadband OPA or OPG in nonlinear materials. The system parameters such as the nonlinear material, pump wavelengths, quasi-phase matching periods, and temperatures can be selected to utilize the intrinsic dispersion relations for such material to produce bandwidth limited or nearly bandwidth limited pulse compression. Compact high average power sources of short optical pulses tunable in the wavelength range of 1800-2100 nm and after frequency doubling in the wavelength range of 900-1050 nm can be used as a pump for the ultra broadband OPA or OPG. In certain embodiments, these short pump pulses are obtained from an Er fiber oscillator at about 1550 nm, amplified in Er fiber, Raman-shifted to 1800-2100 nm, stretched in a fiber stretcher, and amplified in Tm-doped fiber.