Abstract: Inventive single cavities for use in a high power fiber laser systems are described that include a high reflective grating, a gain fiber, an output coupler having a bandwidth in the range of 1 nm to 2 nm; and an output fiber connected to the single cavity that supplies power from the single cavity. The single cavity can be used in a wide variety of applications, including welding, cutting, brazing or drilling a material, or to seed a downstream amplifier.

Abstract: A method of generating high-power laser output in the 1100 to 1500 um spectral region having a controllable linewidth. A Raman amplifier comprised of one or more nested pairs of fiber Bragg grating cavities tuned to the 1st, 2nd, . . . N?1st order Stokes wavelengths is seeded with both the desired Nth order Stokes output wavelength and the corresponding zeroth-order Stokes pump wavelength. As the pump wavelength propagates through the apparatus, it is sequentially converted to the 1st, 2nd, . . . N?1st order Stokes wavelengths in the nested fiber Bragg grating cavities. The desired Nth order Stokes output wavelength is then amplified by the N?1st Stokes order as it propagates through the nested fiber Bragg grating cavities. The linewidths of various Stokes orders can be controlled through adjusting resonant bandwidths of the fiber Bragg grating cavities by offsetting, through heating, the reflectivity bandwidths of each pair of cavity gratings.

Abstract: A laser glass fiber with a core of the fiber comprising a germanosilicate glass host, one or more glass network modifiers, one or more glass network intermediators, and Thulium ions, Holmium ions, or a combination of Thulium ions and Holmium ions. The fiber emits laser light from 1.7 micron to 2.2 micron.

Abstract: A system and method for cooling an optical fiber includes a flexible heat sink member, a heat pipe evaporator, and a thermal storage medium. The flexible heat sink member is in thermal contact with the optical fiber. The heat pipe evaporator is configured to dissipate heat from the optical fiber. The thermal storage medium is in thermal contact with the flexible heat sink member and the heat pipe evaporator. The flexible heat sink member is configured to compensate for any mismatch in coefficient of thermal expansion between material of the optical fiber and material of the flexible heat sink member so as to provide radial compliance and to maintain direct thermal contact between the optical fiber and the flexible heat sink member.

Abstract: A source of optical supercontinuum radiation is disclosed, for generating blue-enhanced spectral components using a pump wavelength of substantially 1064 nm. The source comprises a microstructured optical fibre and a pump laser arranged to generate lasing radiation at the pump wavelength of substantially 1064 nm. The microstructured optical fibre comprises a core region and a cladding region which surrounds the core region and the pump laser is adapted to launch the lasing radiation at the pump wavelength into the core region of the microstructured optical fiber to excite the fundamental mode of the fibre. The fiber comprises a zero dispersion wavelength within ±200 nm of the pump wavelength and can support a plurality of modes at the pump wavelength.

Abstract: A system and method for efficiently combining multiple laser beams into a single frequency by invoking stimulated Brillouin scattering (SBS) in a dual core optical fiber is disclosed. The method and apparatus essentially becomes a brightness converter for the input laser beams. An SRS seed is generated in a long length of fiber or by a diode and is launched into the back-end of the SBS combining optical fiber. Various single-frequency pump beams are launched into the front-end of the same fiber. The seed acts to lower a threshold for SBS in the fiber, thus invoking the nonlinearity. Provided the various pump beams are close in frequency and seed/pump modes overlap, each acts to amplify the seed through the nonlinear SBS process, providing an output signal which is brighter than the combined pump beams.

Abstract: Modelocked fiber laser resonators may be coupled with optical amplifiers. An isolator optionally may separate the resonator from the amplifier. A reflective optical element on one end of the resonator having a relatively low reflectivity may be employed to couple light from the resonator to the amplifier. Enhanced pulse-width control may be provided with concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers. Apodized fiber Bragg gratings and integrated fiber polarizers may also be included in the laser cavity to assist in linearly polarizing the output of the cavity. Very short pulses with a large optical bandwidth may be obtained by matching the dispersion value of the grating to the inverse of the dispersion of the intra-cavity fiber. Frequency comb sources may be constructed from such modelocked fiber oscillators. Low dispersion and an in-line interferometer that provides feedback may assist in controlling the frequency components output from the comb source.

Abstract: The invention relates to a fiber laser comprising a ring-shaped resonator (3). A first section of the resonator is formed by an optical fiber (7) while a second section of the resonator is formed by an optically pumped amplifier fiber (8). The fiber laser further comprises an injection point (4) for injecting light of a pump light source (1) into the resonator (3) as well as an extraction point (5) for extracting generated laser light from the resonator (3). The aim of the invention is to design a more developed fiber laser. The aim is achieved by providing the resonator (3) with at least one reflective optical component (12, 51) which reflects the laser light circulating in the resonator (3).

Abstract: The invention provides an amplification optical fiber, which can output light with a good beam quality even when a higher-order mode is excited, and an optical fiber amplifier using the amplification optical fiber. An amplification optical fiber 50 has a core 51 and a clad 52 covering the core 51. The core 51 propagates light with a predetermined wavelength in at least an LP01 mode, and an LP02 mode, and an LP03 mode. When the LP01 mode, the LP02 mode, and the LP03 mode are standardized by power, in at least a part of a region where the intensity of the LP01 mode is larger than at least one of the intensities of the LP02 mode and the LP03 mode, the active element is added to the core 51 at a higher concentration than the central portion of the core.

Abstract: Techniques and architecture are disclosed for controlling the temperature of a fiber laser system. In some embodiments, a single thermoelectric cooler (TEC) may be utilized to control the temperature of multiple system components. In some embodiments, a TEC may be physically/thermally coupled to a laser diode, which in turn may be physically/thermally coupled with a mounting plate to which one or more fiber grating holders are physically/thermally coupled, and an optical fiber that is operatively coupled with the laser diode may be physically/thermally coupled with the one or more fiber grating holders. In some embodiments, this may provide a thermal pathway/coupling between the optical fiber (e.g., its fiber grating(s)), and the TEC. In some embodiments, this may reduce/minimize the quantity of temperature control components, reduce system size/complexity, increase system dependability, and/or increase system performance/efficiency.

Abstract: A laser for emitting simultaneously a first and second laser lights having respectively first and second wavelength differing from each other. The laser comprises: an optical resonator defining a first optical path and a second optical path, the first laser light travelling along the first optical path and the second laser light travelling along the second optical path; a modulated gain element inserted in the optical resonator for amplifying the first and second laser lights as the first and second laser lights propagate in the optical resonator respectively along the first and second optical paths, the modulated gain element having a variable gain modulated with a modulation period, round trip times of the first and second laser lights along respectively the first and second optical paths being respective integer multiples of the modulation period; and an output port for releasing the first and sec and laser lights from the optical resonator.

Abstract: A laser source includes a laser device configured to emit laser light at a given angle with respect to a normal of an output end face; and an optical device configured to include an optical waveguide that guides and outputs the laser light. The output end face of the laser device is parallel to an input end face of the optical device, and the optical waveguide extends in a direction of ?w1 that is given by ?w1=arcsin(sin ?a1/nF), where ?a1 denotes an outgoing angle of the laser light from the laser device, and nF denotes an effective refractive index of the optical waveguide for the laser light.

Abstract: A fiber laser system is configured with a power measuring assembly surrounding a splice between two fibers. The power measuring assembly is operative to maintain the splice at a substantially constant splice temperature and shield the spliced fibers from external bending stresses so as to provide for power readings of the laser system at the splice independently from the influence of multiple variable external factors.

Abstract: The invention is an apparatus and method for free space pumping of active double-clad fiber based lasers and amplifiers. The apparatus comprises a laser emitting a signal laser beam; an active double-clad fiber having a core defining an optical axis of the apparatus and a pump cladding defining a cone of numerical aperture; an optical arrangement directing the signal laser beam along the optical axis through the core of the active double-clad fiber; at least one pump source emitting a pump beam; at least one delivery means coupling the pump beam to the pump cladding of the active double-clad fiber; and an optical arrangement coupling the amplified signal laser beam exiting the active double-clad fiber out of the apparatus.

Abstract: When an output instruction is input to the control unit, the control unit controls the seed laser light source and the pumping light source to be either in a pre-pumped state or in an output state. In the pre-pumped state, laser light is not output from the seed laser light source, and pumping light with a predetermined intensity based on a laser light intensity set by the output setting unit is output from the pumping light source for a certain period of time. In the output state, laser light is output from the seed laser light source, and pumping light is output from the pumping light source, so that laser light with the intensity set by the output setting unit is output.

Abstract: The laser includes an optical fiber including a cavity containing a microfluidic gain medium bounded by a composite structure of alternating layers of high and low index materials forming an axially invariant, rotationally symmetric photonic bandgap cavity. The optical fiber also includes at least one microfluidic channel containing liquid crystal modulators in the fiber cladding extending in an axial direction and further includes a pair of electrodes flanking the microfluidic channel. An electrical potential across the pair of electrodes will rotate the liquid crystal molecules to rotate the linearly polarized state of light emitted from the cavity. An external linear polarizer is disposed around the fiber to modulate azimuthal laser intensity distribution.

Abstract: A laser apparatus includes an optical fiber component and a pump light source coupled to the optical fiber component. The optical fiber component includes a first fiber segment, a second fiber segment and a connecting segment that connects the first and second fiber segments. The first fiber segment includes a fiber core having a first diameter, and the second fiber segment includes a fiber core having a second diameter. The first diameter may be greater than the second diameter, and the connecting segment may have a periodically varying refractive index.

Abstract: A compact, light weight laser beam combiner includes a pair of concentric annular shells defining an annular cavity of an annular ring resonator having an annular solid laser gain medium disposed therein. The output ends of a plurality of low power and brightness fiber lasers are coupled into the cavity of the resonator such that fiber laser beams cause the gain medium in the resonator cavity to lase and produce an annular beam of laser light. Optical elements of the resonator are operable to feed a first portion of the laser light back through the resonator cavity to support regenerative lasing of the laser medium and to couple off a second portion of the laser light in the form of a circular beam of high power and high brightness laser light. A fluid may be circulated through the resonator cavity to cool the laser medium.

Abstract: Techniques are disclosed for improving pump absorption and efficiency for fiber lasers and amplifiers, for instance. In some embodiments, the techniques are implemented by applying a partially reflective coating on a fiber end-face to double-pass any unabsorbed or otherwise excess pump light in the cladding of a fiber. While being reflective to pump wavelengths, the coating can be non-reflective at the lasing wavelength, so as to avoid unwanted feedback into the system. The benefits of this approach include that excess pump power can be effectively utilized to add more power to the laser output. In addition, the double-pass technique allows for the use of a shorter fiber length, which in turn allows for more compact system designs, saves on material costs, and facilitates manufacturability.

Abstract: The laser light emitting device includes a glass rod having an input end and an output end. The glass rod has a core provided along the central axis thereof and a cladding covering the core. The refractive index of the core on the side of the input end is higher than the refractive index of the cladding. A value given through subtraction of the refractive index of the cladding from the refractive index of the core on the side of the output end is smaller than a value given through subtraction of the refractive index of the cladding from the refractive index of the core on the side of the input end.

Abstract: An optical supercontinuum radiation source for generating a broad optical supercontinuum from pump radiation having a wavelength in the range 900 nm to 1200 nm includes a microstructured optical fiber and a pump laser adapted to generate pump radiation for pumping the microstructured optical fiber. The fiber can have a ? (“delta”) value of greater than 0.3, the core region of the fiber can support a plurality of modes at the pump wavelength, and the cladding region can comprise at least two air holes extending along the length of fiber wherein the ratio of the diameter (d) of the air holes to their pitch (?) is greater than 0.6. The fiber can comprise a zero dispersion wavelength (ZDW) within ±200 nm of said pump wavelength.

Abstract: Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers.

Abstract: Various embodiments include large cores fibers that can propagate few modes or a single mode while introducing loss to higher order modes. Some of these fibers are holey fibers that comprising cladding features such as air-holes. Additional embodiments described herein include holey rods. The rods and fibers may be used in many optical systems including optical amplification systems, lasers, short pulse generators, Q-switched lasers, etc. and may be used for example for micromachining.

Abstract: The present invention relates to a white light source, and particularly to a white light source with crystal fiber and a method for color temperature tuning thereof. The white light source of the present invention comprises a pumping source for providing a first-color light, and a gradient index lens for coupling the first-color light into a crystal fiber. The crystal fiber absorbs a portion of the first-color light and generates a second-color light and a third-color light, and a white light with high color rendering index can be obtained. The crystal fiber is made of a first rare earth element oxide and a second rare earth element oxide co-doped yttrium aluminum garnet. The color temperature of the white light can be tuned by adjusting the position of the focus of the pumping light on the end section of the crystal fiber.

Abstract: A gain module, operative to output a laser light coupled into a laser system, is structured with at least one gain element radiating the laser light and a spectrally-selective element. The spectrally-selective element includes a slab of photosensitive material and two parallel feedback and isolating Bragg mirrors recorded in the slab. The feedback Bragg mirror is operative to provide a wavelength-dependent feedback so as to cause the laser chip to generate the laser light at the resonance wavelength of the feedback Bragg mirror. The isolating Bragg mirror is automatically adjusted to retroreflect a backreflected signal light, which is generated by the laser system at a signal wavelength different from the resonance wavelength, upon positioning the feedback mirror orthogonally to the laser light.

Abstract: A modelocked fiber laser is designed to have strong pulse-shaping based on spectral filtering of a highly-chirped pulse in the laser cavity. The laser generates femtosecond pulses without a dispersive delay line or anomalous dispersion in the cavity.

Abstract: A laser apparatus uses a dysprosium doped chalcogenide glass fiber. The glass fiber has a laser pump operatively connected to it. The chalcogenide glass fiber is located in a laser cavity including one or more reflective elements such as a Bragg grating, a Bragg minor, a grating, and a non-doped fiber end face. The apparatus provides laser light output at a wavelength of about 4.3 ?m to about 5.0 ?m at a useful power level using laser light input at a wavelength of from about 1.7 ?m to about 1.8 ?m. Also disclosed is a method for providing laser light output at a wavelength of about 4.3 ?m to about 5.0 ?m using the apparatus of the invention.

Abstract: A Brillouin laser having a narrowed linewidth, reduced relative intensity noise, and increased output power includes a pump laser that provides pump energy to an optical fiber resonant cavity to stimulate Brillouin emission. The output of pump laser is stabilized and its linewidth is narrowed by locking the frequency and phase of the optical signal generated by the pump laser to a longitudinal mode of the optical fiber resonant cavity. In addition, the resonant cavity is temperature and/or strain-tuned so that the Brillouin gain is substantially centered on a longitudinal mode of the cavity, thereby ensuring that the Brillouin frequency shift is substantially equal to an integer number of the free spectral range of the cavity.

Abstract: Apparatus and method for control of lasers (which use an array of optical gain fibers) in order to improve spectrally beam-combined (SBC) laser beam quality along the plane of the SBC fiber array via spectral-to-spatial mapping of a portion of the spectrally beam-combined laser beams, detection of optical power in each of the spatially dispersed beams and feedback control of the lasers for wavelength-drift correction. The apparatus includes a diffractive element; a source of a plurality of substantially monochromatic light beams directed from different angles to a single location on the diffractive element, wherein the diffractive element spectrally combines the plurality of light beams into a single beam. A controller adjusts characteristics of the light beams if one of the light beams has become misadjusted. In some embodiments, the controller adjusts the wavelength tuning of the respective fiber laser.

Abstract: A fiber laser includes: a seed light source; a preamplifier unit including a first optical fiber doped with a first rare earth element and amplifying a pulse seed light; a main amplifier unit including a second optical fiber doped with a second rare earth element and the first rare earth element and further amplifying light amplified by the preamplifier unit; and a buffer optical fiber provided between the preamplifier unit and the main amplifier unit, and doped with the second rare earth element. Amplified spontaneous emission light emitted by energy stored in the second rare earth element and the second excitation light not absorbed into the first and second rare earth elements of the second optical fiber but remaining are absorbed into the second rare earth element of the buffer optical fiber.

Abstract: A fiber laser device includes: a laser oscillator to emit laser light having a first wavelength; a first optical filter to transmit the laser light having the first wavelength; a wavelength converter to generate laser light having a second wavelength using stimulated Raman scattering caused by the laser light having the first wavelength and transmit the laser light having the first wavelength and the laser light having the second wavelength; and a second optical filter to transmit the laser light having the second wavelength and prevent transmission of laser light having the first wavelength. The laser light having the second wavelength that has passed through the second optical filter travels through an optical fiber amplifier and an output end. The first optical filter, the wavelength converter and the second optical filter are each constituted by a photonic band gap fiber.

Abstract: The present invention relates to a fiber laser system for processing materials involving a system of interconnected operational components for combining and optionally distributing beams from multiple beam emitters. More particularly, the present invention provides a system for combining and distributing fiber laser beams having different wavelengths and a method for operating the system thereof. Multiple beam combiners may be optionally linked with a beam distribution system. In exemplary use, multiple fiber laser sources generating different wavelength outputs are combined in a single beam incident of a work piece comprising multiple layers.

Abstract: A glass composition for use as a laser medium, a method for producing the glass composition, and a laser apparatus including the glass composition are provided. The glass composition includes a host glass; a 3p component having a concentration of about 5 mole percent to about 10 mole percent; and at least one of a 6p component having a concentration of about 1 mole percent to about 5 mole percent and a 5p component having a concentration of about 1 mole percent to about 5 mole percent.

Abstract: To provide an optical nanofiber resonator having an optical waveguide whose diameter is equal to or smaller than the wavelength of a propagation light, a light emitter disposed at a predetermined position of the optical waveguide, and a first reflector and a second reflector formed in the optical waveguide with the light emitter interposed therebetween, wherein at least one of the first reflector and the second reflector transmits a part of the propagation light. With such a configuration, the channeling efficiency of the light emitted from the light emitter and the propagation mode of the optical waveguide is dramatically improved.

Abstract: Methods and systems for generating a supercontinuum light source, including generating electromagnetic radiation from a seed laser; coupling the seed laser electromagnetic radiation to a fiber amplifier comprising: a pump laser, a fiber coupler comprising an input and an output, and a nonlinear gain fiber comprising an input and an output, wherein the nonlinear gain fiber is configured to amplify and broaden the electromagnetic radiation from the seed laser; generating electromagnetic radiation from the pump laser; coupling the pump laser electromagnetic radiation and the seed laser electromagnetic radiation into the input of the fiber coupler; coupling the output of the fiber coupler into the input of the nonlinear gain fiber; and coupling out the amplified and broadened electromagnetic radiation from the nonlinear gain fiber. Other embodiments are described and claimed.

Abstract: Laser master oscillator—power amplifier system for generating high pulse energy, high average power laser pulses in the ultraviolet 191.25-201.25 nm and 243-246.25 nm spectral ranges, and in the visible 450-537.5 nm spectral range with controllable pulse duration and pulse repetition rate employ a master oscillator seed laser operating in the infra-red spectral range, and a single series connected chain of hybrid fiber—bulk crystalline amplifiers coupled to a non-linear frequency conversion unit to convert the laser pulses to the ultraviolet and visible spectral ranges.

Abstract: Fundamental-wavelength pulses from a fiber a laser are divided into three or more pulse portions and the three or more portions are separately amplified. Two or more of the amplified fundamental-wavelength pulse-portions are combined and frequency-doubled. The frequency doubled portion is sum-frequency mixed with one or more of the other amplified fundamental wavelength pulse-portions to provide third-harmonic radiation pulses.

Abstract: When an output instruction is input to a control unit, the control unit controls a seed laser light source and a pumping light source to be either in a pre-pumped state or in an output state. In the pre-pumped state, the pumping light source outputs, for a predetermined period, pumping light with an intensity determined based on the duration of the period of time from when the output state prior to the input of the output instruction to the control unit comes to an end till when the output instruction is input to the control unit. In the output state, to cause the output unit to output laser light, the seed laser light source outputs laser light, and the pumping light source outputs pumping light.

Abstract: A pulsed fiber laser including fiber preamplifier and power amplifier stages is disclosed. A fiber preamplifier includes first and second preamplifier stages that receive and amplify a seed pulse. A filter isolator placed between the preamplifier stages suppresses noise from the first preamplifier stage. An acoustic optical modulator located in the second preamplifier stage eliminates unwanted wavelengths from the amplified seed pulse received from the first preamplifier stage. The pulsed fiber laser is rugged and lightweight.

Abstract: The present invention relates to a MOPA light source capable of obtaining pulse output by wavelength-conversion of pulse light of fundamental light wave using a simple configuration, and suppressing optical output using a simple method when processing is not performed. The fundamental light wave outputted from a seed light source is amplified in an optical amplification fiber. The amplified fundamental light wave is inputted to one end of a passive optical fiber, and propagates in the passive optical fiber. In the passive optical fiber, stimulated Raman scattering occurs upon propagation of the fundamental light wave. The light of fundamental light wave and light of stimulated Raman-scattered components are outputted from the other end of the passive optical fiber. The light outputted from the passive optical fiber is collimated by a lens, and is then inputted to a branching filter.

Abstract: A method for arranging a high power fiber laser system includes spiraling an active fiber in a housing with a diameter of spiral gradually decreasing towards the center of th housing. The method further includes coupling the opposite free ends of the spiraled active fiber to respective passive fibers providing optical communication between the active fiber and discrete components. Thereafter, the passive fibers with the discrete components are arranged next to inner spirals of the active fiber.

Abstract: A method for manufacturing an optical fiber grating that includes first and second gratings that configure an optical resonator, the method including: forming the first grating by radiating ultraviolet light to an optical fiber so that a irradiation intensity Z satisfies the following Equation 1: Z?(??S/x+0.04556 Y2+1.2225 Y)/(0.05625 Y2+1.6125 Y) . . . Equation 1, where, Z represents an irradiation intensity (mJ/mm2) of the ultraviolet light, ??S represents the maximum shift amount of a reflection center wavelength of the first grating that is allowed as long as reflection wavelengths of the first grating and second grating overlap each other, x represents a shift amount of the reflection center wavelength per temperature change of 1° C. (nm/° C.) in the first grating, and Y represents an intensity (W) of the wave-guided light.

Abstract: A CW ytterbium-doped fiber-laser includes a gain-fiber having a reflector proximity-coupled to one end, with the other end left uncoated. A laser resonator is defined by the reflector and the uncoated end of the gain-fiber. Pump-radiation from fast-axis diode-laser bar-stacks emitting at 915 nm and 976 nm is combined and focused into the uncoated end of the gain-fiber for energizing the fiber. Laser radiation resulting from the energizing is delivered from the uncoated end of the gain-fiber and separated from the pump-radiation by a dichroic minor.

Abstract: A device is provided that includes an optical fiber and an assembly illuminating the optical fiber capable of illuminating the optical fiber at an upstream end. The optical fiber includes a hollow core and an anti-resonant annular cladding arranged around the hollow core. The illuminating assembly generates a focused beam of Airy spot shape for injection into the input of the optical fiber.

Abstract: A laser diode driving device (1) of the present invention includes: a variable DC power supply (3) for outputting a voltage for driving laser diodes (LD1 to LDn); a current driving element (4) for causing a current If to flow; a current control section (5) for controlling (i) turning on and off of the current driving element (4) and (ii) the amount of the current If; and a power supply control section (7) for controlling an output voltage of the variable DC power supply (3). The power supply control section (7) controls, on the basis of If-Vf characteristic data (D2), voltage drop characteristic data (D3), and Vds setting data (D4) all stored in a memory section (8), the output voltage of the variable DC power supply (3) so that the current driving element (4) has a constant inter-terminal voltage regardless of the amount of the current If.

Abstract: A fiber laser system includes: a fiber laser device (10) including a fiber laser (11); a laser output end part (20); and a delivery fiber (30). The delivery fiber (30) is constituted by a double cladding fiber. On the output end side of the delivery fiber (30), there is provided an SFBG (31) which reflects part of laser light propagating in the core of the delivery fiber (30) to thereby couple the part of the laser light with a backward-propagating cladding mode propagating in a first cladding in a backward direction. On the input end side of the delivery fiber (30), there is provided a backward-propagating cladding mode detecting section (32) which detects the intensity of backward-propagating light in a cladding mode, which light is the part of the laser light coupled by the SFBG (31) with the backward-propagating cladding mode.

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for generating terahertz electromagnetic radiation. According to an example embodiment of the invention, a method is provided for generating terahertz electromagnetic radiation. The method includes: coupling a terahertz resonator with an optical resonator, wherein the optical resonator comprises non-linear optical material; directing laser light through the optical resonator to generate terahertz radiation by parametric interaction of the laser light with the optical resonator and the terahertz resonator; and directing the terahertz radiation from the terahertz resonator to an output.

Abstract: A high power cladding light stripper and high power laser systems using the same are described. A cladding light stripper includes a housing, a section of fiber disposed in relation to the housing wherein a portion of the section of fiber has an exposed cladding region, a plurality of glue regions sequentially arranged adjacent to each other along the section of fiber and covering the exposed cladding region, and wherein at least one glue region between a first glue region and a last glue region of the plurality of glue regions has a refractive index higher or lower than both an adjacent previous glue region and an adjacent subsequent glue region.

Abstract: An optical fiber amplifier (2) includes: a first pumping source (10); a second pumping source (20); an amplification optical fiber (3) in which an active element is doped; a first optical filter (15) coupled to the first pumping source (10) and one end of the amplification optical fiber (30), the first optical filter (15) transmitting a light at a wavelength the same as the wavelength of a first pumping light and reflecting a light at a wavelength the same as the wavelength of a second pumping light; and a second optical filter (25) coupled to the second pumping source (20) and the other end of the amplification optical fiber (3), the second optical filter (25) transmitting a light at a wavelength the same as the wavelength of the second pumping light and reflecting a light at a wavelength the same as the wavelength of the first pumping light.

Abstract: There are provided: a core section provided so as to extend in a light-guiding direction in which incident light propagates; a photosensitive layer provided so as to extend in the light-guiding direction and peripherally enclose the core section, the photosensitive layer including a grating formed therein by irradiation of ultraviolet light having a predetermined wavelength; and a first cladding section provided between the core section and the photosensitive layer, the first cladding section having a lower refractive index than the core section and a lower photosensitivity than the photosensitive layer, the photosensitivity being a property in which a refractive index changes in response to irradiation with the ultraviolet light.