Abstract: A clad absorber unit is provided on a passive fiber of a high power fiber laser system and operative to trap and remove modes propagating along the waveguide clad of the fiber. The mode absorber is configured with such an optimal length that the clad light may be removed in a localized manner, substantially uniformly removed over the entire length thereof. The absorber removing clad light in a unformed fashion includes a host material impregnated with diffusers.

Abstract: Implementations and examples of fiber lasers based on fiber laser cavity designs that produce self-similar pulses (“similaritons”) to achieve a pulse spectral bandwidth greater than a gain spectral bandwidth based on a spectral broadening fiber segment and a spectral filter to ensure the proper similariton conditions.

Abstract: The invention relates to a laser device, comprising a laser configured to generate laser light and a laser control module configured to receive at least a portion of the laser light generated by the laser, to generate a control signal and to feed the control signal back to the laser for stabilizing the frequency, wherein the laser control module comprises a tunable frequency discriminating element which is preferably continuously frequency tunable, and where the laser control module is placed outside the laser cavity.

Abstract: A laser anti-reflection device includes a polarizing beam splitter, a ?/4 wave plate and an absorber disposed in an outgoing light path of a laser emitting linearly polarized light with a wavelength of ?. The linearly polarized light from the laser passes through the polarizing beam splitter and the ?/4 wave plate in turn to become a circularly polarized light beam. Part of the circularly polarized light beam is then reflected by a workpiece to be processed along the original light path and passes the ?/4 wave plate to become a linearly polarized light beam with a polarization direction vertical to that of the outgoing linearly polarized light beam. The vertical polarized beam passes the polarizing beam splitter, deviates from the light path of the outgoing linearly polarized light beam and reaches the absorber. The laser anti-reflection device prevents reflected light from damaging the laser from high power lasers.

Abstract: A device for transformation of concentrated solar energy including a photovoltaic cell and laser device, which includes a first reflecting mirror adapted for entry of a beam of solar rays and a second reflecting mirror adapted for an outlet of a laser beam, with the first reflecting mirror reflective on an outlet wavelength of the laser beam and transparent to a totality of a solar spectrum and the second reflecting mirror partially reflective on the wavelength of the laser beam, reflective in an interval of the solar spectrum which is absorbed and transparent in other wavelengths different to these, and at the outlet of the laser beam. The device includes a nucleus doped with substances for total or partial absorption of the solar spectrum and coatings.

Abstract: An apparatus, method and system that uses a Q-switched laser or a Q-seed source for a seed pulse signal having a controlled high-dynamic-range amplitude that avoids and/or compensates for pulse steepening in high-gain optical-fiber and/or optical-rod amplification of optical pulses. Optionally, the optical output is used for LIDAR or illumination purposes (e.g., for image acquisition). In some embodiments, well-controlled pulse shapes are obtained having a wide dynamic range, long duration, and not-too-narrow linewidth. In some embodiments, upon the opening of a Q-switch in an optical cavity having a gain medium, the amplification builds relatively slowly, wherein each round trip through the gain medium increases the amplitude of the optical pulse. Other embodiments use quasi-Q-switch devices or a plurality of amplitude modulators to obtain Q-seed pulses.

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.

Abstract: In at least one embodiment, a wavelength-tunable light source includes at least one fiber-based partial section and at least one delay section. For a wavelength ? of at least one portion of a radiation emitted by the light source as a function of time t, the relationship ?(t)=?(t??) holds true. In this case, ? is a specific period of time. Furthermore, the delay section includes one or more oligomode fibers.

Abstract: A pulsed fiber laser oscillator comprising in succession: a pumping source (10) for providing pumping energy at a first wavelength to a multimode optical fiber; a first Bragg grating optical filter (11) reflecting a second wavelength and transparent to said first wavelength; an active optical fiber (20) having a predefined wavelength which emits radiation at said second wavelength; a switch (14) arranged to periodically interrupt said second wavelength to provide a pulsed laser beam; and a second Bragg grating optical filter (15) partially reflecting said second wavelength; characterized by comprising, following said active optical fiber (20), a reflector (21) of said first wavelength, such that said pumping energy undergoes two passages within said active optical fiber (20); said predefined wavelength being determined such that the absorption of said pumping energy at said first wavelength within said active optical fiber (20) is greater than 80% after undergoing said two passages.

Abstract: An improved system for safe and efficient generation of plasmas and vapors bubbles with continuous wave radiations and low levels of power densities, sufficient to treat medical pathologies and to avoid the creation damage to healthy tissue is provided. Transmission means in different configurations are used to achieve a high absorption in water, which is able to initiate plasma with low levels of power density. Once plasma and vapor bubbles are formed, they absorb other wavelengths in addition to the one that initiated it. Other wavelengths, more efficiently generated by diodes or diode pumped lasers, are added into the beam to improve treatment efficiency. This modulated plasma produces fast tissue ablation and good hemostasis effect with minimal overheating of remaining tissue. After plasma and high-energy vapors are generated, only laser radiation that passes through the plasma bubble directly interacts with soft tissues.

Abstract: A laser for generating an output wavelength of approximately 193.4 nm includes a fundamental laser, an optical parametric generator, a fourth harmonic generator, and a frequency mixing module. The optical parametric generator, which is coupled to the fundamental laser, can generate a down-converted signal. The fourth harmonic generator, which may be coupled to the optical parametric generator or the fundamental laser, can generate a fourth harmonic. The frequency mixing module, which is coupled to the optical parametric generator and the fourth harmonic generator, can generate a laser output at a frequency equal to a sum of the fourth harmonic and twice a frequency of the down-converted signal.

Abstract: Optical pump modules comprising VCSEL and VCSEL array devices provide high optical power for configuring fiber optic gain systems such as fiber laser and fiber amplifier particularly suited for high power operation. Pump modules may be constructed using two reflector or three reflector VCSEL devices optionally integrated with microlens arrays and other optical components, to couple high power pump beams to an optical fiber output port, particularly suited to couple light to an inner cladding of a double-clad fiber suitable for a high power gain element. Multiple-pumps may be combined to increase pump power in a modular fashion without significant distortion to signal, particularly for short pulse operation. The pump modules may be operated in CW, QCW and pulse modes to configure fiber lasers and amplifiers using single end, dual end, and regenerative optical pumping modes.

Abstract: According to one embodiment, the invention relates to a laser gain module (1) comprising: a laser rod (5) having a shaft and two optical interfaces (7, 9) facing each other, the rod (5) being used for longitudinal or quasi-longitudinal optical pumping; and a metal cooling body (3), at least one part of which is molded around the laser rod (5) in order to cover all of the surfaces other than the optical interfaces in such a way that the laser gain module (1) forms a solid body that cannot be disassembled at ambient temperature.

Abstract: A high-power optical fiber laser includes: an oscillator (1); a pumping laser (5) able to emit a high-power pumping optical radiation beam; and a signal-amplifying optical fiber (3) able to receive the optical source signal and the high-power pumping optical radiation beam so as to generate a high-power laser beam. The pumping laser includes a plurality of pumping multimode laser diodes (7a-7f) and a laser cavity, the laser cavity including a double-clad fiber (4) including: a neodymium-doped monomode waveguide; a fiber Bragg grating (9) forming one end of the laser cavity; and a fiber reflector (11) forming the other end of the laser cavity, the monomodefiber laser being able to generate a laser radiation beam when it is optically pumped by a pumping radiation beam originating from the plurality of pumping laser diodes in order for the laser cavity to emit a high-power pumping laser radiation beam.

Abstract: A third-order distributed feedback laser has an active medium disposed on a substrate as a linear array of segments having a series of periodically spaced interstices therebetween and a first conductive layer disposed on a surface of the active medium on each of the segments and along a strip from each of the segments to a conductive electrical contact pad for application of current along a path including the active medium. Upon application of a current through the active medium, the active medium functions as an optical waveguide, and there is established an alternating electric field, at a THz frequency, both in the active medium and emerging from the interstices. Spacing of adjacent segments is approximately half of a wavelength of the THz frequency in free space or an odd integral multiple thereof, so that the linear array has a coherence length greater than the length of the linear array.

Abstract: Optical pulse source comprising optical pump laser for generating optical pump pulses at repetition rate Rf; a nonlinear optical element comprising an optical fiber for generating supercontinuum pulses; a gating device provided operable to selectively control the launch of pump pulses into the optical fiber at a reduced, lower repetition rate Rr=Rf/N in order to generate supercontinuum pulses at different user selectable repetition rates lower than the pump pulse repetition rate; first and second optical amplifiers; wavelength tunable optical bandpass filter; wherein the optical fiber can generate supercontinuum pulses having a supercontinuum spanning from below 450 nm to greater than 2000 nm; and wherein said optical pulse source comprises an all-fiber source wherein said optical pump laser comprises a fiber oscillator, said gating device comprises a fiber coupled optical modulator, and the optical pump pulses are launched into the optical fiber without the use of free space optics.

Abstract: The invention relates to a mode filter for reducing higher-order modes, with an optical fibre (1), which has a core (2) and a cladding (3) surrounding the latter, wherein the cladding (3) and core (2) have refractive indices that differ from one another. In order to develop an alternative to the prior art, the mode filter according to the invention is designed in such a manner that the fibre (1) has, in a transition region (4) between core (2) and cladding (3), at least one local refractive index modification region (5) which is arranged in the radially outer region of the core (2) and extends into the region of the cladding (3).

Abstract: A clad absorber unit is provided on a passive fiber of a high power fiber laser system and operative to trap and remove modes propagating along the waveguide clad of the fiber. The mode absorber is configured with such an optimal length that the clad light may be removed in a localized manner, substantially uniformly removed over the entire length thereof. The absorber removing clad light in a unformed fashion includes a host material impregnated with diffusers.

Abstract: An improved fiber array arrangement is provided that incorporates spacing and/or spacers between active fibers in a winding to reduce maximum active fiber temperature, with the spacing/spacer material distributed to minimize heating at locations of high pump power. Spacer material such as “dark” fibers and/or metal wires of similar diameter as the active fiber may be employed to aid winding/bundling of active fibers. Further, the use of channels, grooves, wall material and combinations thereof aid structural support/guidance for the winding/bundling of active fibers while providing predefined spacing and heat conductivity that reduces the maximum thermal temperature of the active fiber below design thresholds.

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: An Environmentally stable optical fiber mode-locked laser generating device having an achromatic quarter wave plate is disclosed. An optical fiber unit is formed of a polarization maintaining (PM) optical fiber, and a Bragg grating is formed on a first region from one end in direction to the other end, a gain material is doped on a core of a remaining second region. An optical coupling unit provides a pump laser input to one end of the optical fiber unit, and outputs a laser input from the optical fiber unit. A lens unit converts a laser output from the other end of the optical fiber unit and focuses the laser on a certain regime.

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: 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: A fiber laser having a ring resonance path comprises a pump light source, a Yb-doped optical fiber and a light modulation unit. The pump light source emits a pump light. The Yb-doped optical fiber is coupled with the pump light. The light modulation unit includes a grating pair, a diaphragm and two reflective elements. The grating pair is coupled with the pump light. The diaphragm includes an aperture. The light transmitted by the grating pair partially passes through the aperture and reaches one of the reflective elements to become a reflective light, and the reflective light passes through the aperture and is transmitted through the grating pair and the other reflective element to be coupled back with the ring resonance path.

Abstract: A fiber laser includes: an amplification optical fiber; a pumping light source configured to emit pumping light to pump the active element of the amplification optical fiber; a first mirror provided on one side of the amplification optical fiber; and a second mirror provided on the other side of the amplification optical fiber. When an optical loss between the first mirror and the second mirror is equal to an optical gain in the amplification optical fiber, a difference between a gain of light having a wavelength at which a gain becomes maximum and a gain of light having a wavelength reflected off the first mirror and the second mirror is 35 dB or less in the amplification optical fiber.

Abstract: A fiber laser having a ring resonance path comprises a pump light source, a Yb-doped optical fiber and a light modulation unit. The pump light source emits a pump light. The Yb-doped optical fiber is coupled with the pump light. The light modulation unit includes a grating pair, a diaphragm and two reflective elements. The grating pair is coupled with the pump light. The diaphragm includes an aperture. The light transmitted by the grating pair partially passes through the aperture and reaches one of the reflective elements to become a reflective light, and the reflective light passes through the aperture and is transmitted through the grating pair and the other reflective element to be coupled back with the ring resonance path.

Abstract: The pulse light source comprises a semiconductor laser outputting pulse light, an optical filter, and an optical amplifier. The optical filter outputs a chirping component of the inputted pulse light, by adjusting a relative position of a transmission spectrum of the optical filter with respect to an output spectrum of the seed light source.

Abstract: Frequency standards based on mode-locked fiber lasers, fiber amplifiers and fiber-based ultra-broad bandwidth light sources, and applications of the same.

Abstract: The present invention relates to a method of processing a metal thin film formed on a transparent substrate by radiating pulsed light onto the metal thin film, and having the steps of repeatedly outputting the pulsed light by directly modulating a semiconductor laser of the seed light source in accordance with electric signals, amplifying the pulsed light using an optical amplifier including an optical amplification medium, controlling the full width at half maximum of the pulsed light that is amplified and outputted by the optical amplifier to be 0.5 ns or less, and removing the metal thin film by radiating the pulsed light thus having the controlled full width at half maximum onto the metal thin film through the transparent substrate.

Abstract: Hybrid laser systems include fiber amplifiers using tapered waveguides and solid-state amplifiers. Typically, such systems represent a technically simple and low cost approach to high peak power pulsed laser systems. The tapered waveguides generally are provided with an active dopant such as a rare earth element that is pumped with one or more semiconductor lasers. The active waveguide taper is selected to taper from a single or few mode section to a multimode section. A seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode. The waveguide taper permits amplification to higher peak power values than comparable small mode area fibers. The fiber amplified beam is then directed to a solid state amplifier, such as a thin disk or rod-type laser amplifier.

Abstract: A modular ultrafast pulse laser system is constructed of individually pre-tested components manufactured as modules. The individual modules include an oscillator, pre-amplifier and power amplifier stages, a non-linear amplifier, and a stretcher and compressor. The individual modules can typically be connected by means of simple fiber splices.

Abstract: A laser utilizes a cavity design which allows the stable generation of high peak power pulses from mode-locked multi-mode fiber lasers, greatly extending the peak power limits of conventional mode-locked single-mode fiber lasers. Mode-locking may be induced by insertion of a saturable absorber into the cavity and by inserting one or more mode-filters to ensure the oscillation of the fundamental mode in the multi-mode fiber. The probability of damage of the absorber may be minimized by the insertion of an additional semiconductor optical power limiter into the cavity.

Abstract: A high power fiber laser system includes a booster winch is configured as a fiber amplifier extending over free space, pump source and laser head including a reflective element which receives pump light and reflects toward the output end of the booster in a counter signal-propagating direction. The booster is configured with concentric and coextending frustoconically shaped (“MM”) core and cladding around the core. The core includes a mode transition region expanding between small diameter SM input and large diameter MM output core ends and configured so that amplification of high order modes is substantially suppressed as a single mode (“SM”) signal light propagates from the input to output core ends. The laser head receives output ends of respective pump light delivery fibers and signal fiber, respectively. The pump source is structured with a plurality of independent sub pumps arranged around the booster.

Abstract: An optical active fiber is configured with an asymmetrically-shaped core having at least one long axis and a shortest axis which extends transversely to the long axis. The outmost cladding of the active fiber is configured with a marking indicating the orientation of the short axis. The marking allows for bending the fiber so that the shortest axis extends along and lies in the plane of the bend thereby minimizing distortion of a mode which is guided by the asymmetrically-shaped core as light propagates along the bend.

Abstract: Compact laser systems are disclosed which include ultrafast laser sources in combination with nonlinear crystals or waveguides. In some implementations fiber based mid-IR sources producing very short pulses and/or mid-IR sources based on a mode locked fiber lasers are utilized. A difference frequency generator receives outputs from the ultrafast sources, and generates an output including a difference frequency. The output power from the difference frequency generator can further be enhanced via the implementation of large core dispersion shifted fibers. Exemplary applications of the compact, high brightness mid-IR light sources include medical applications, spectroscopy, ranging, sensing and metrology.

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: The invention describes classes of robust fiber laser systems usable as pulse sources for Nd: or Yb: based regenerative amplifiers intended for industrial settings. The invention modifies adapts and incorporates several recent advances in FCPA systems to use as the input source for this new class of regenerative amplifier.

Abstract: A high power (HP) fiber circulator is configured with a case enclosing a plurality of optical components which are arranged so as to define multiple ports. The fiber circulator further includes a plurality of launching and receiving fiber components each of which has spliced delivery and pigtailed passive fibers selectively coupling a HP input signal into and receiving a HP output signal from respective input and output ports. The passive fibers of each fiber component have respective protective coatings spaced from one another and each covering the cladding of the fibers. A light stripper, extending between the protective coatings, is operative to substantially remove cladding-supported light from one of the passive fibers before it reaches the protective coating of the other passive fiber.

Abstract: Methods and systems for delivery of high peak power optical pulses through optical fiber are disclosed. Raman soliton generation is utilized to maintain the properties of the pulses in the delivery fiber. The apparatus can comprise any high peak power pulse source and delivery fiber supporting Raman soliton generation.

Abstract: An optical pulse source comprising a DPSS pump laser, a photonic crystal fiber (PCF), and acousto-optic modulator (AOM) gating device is disclosed. The pump pulses are coupled through lenses to the AOM gating device, which is synchronized to the pump laser and is operable to gate the pump pulses to a reduced repetition rate Rr=Rf/N, where Rf is the pump laser fundamental frequency. The pulses from the AOM are injected via optics into the PCF. Propagation through the PCF causes the pulses to broaden spectrally to produce optical supercontinuum pulses. An optical pulse source that further includes an acousto-optical tunable filter (AOTF) operable to convert the optical supercontinuum pulses into wavelength variable output pulses is also provided. A method of scaling the energy of the optical supercontinuum pulses is also disclosed.

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 fiber block is configured with a fiber block including a Nd-doped active fiber and a pump-light delivery fiber which has a stretch extending along the active fiber in a side-to-side configuration so as to lunch pump light into the Nd-doped core of the active fiber. The core of the active fiber is surrounded by at least one or more claddings which, like the core, have a double bottleneck cross-section with a relatively large-area central region and relatively small input and output regions. The pump light delivery fiber is structured to have a substantially dumbbell cross-section with a relatively small-area central region coextending with the central region of the active fibers. The active fiber is dimensioned so that the overall length of the active fiber is configured to provide for the maximal amplification of the laser signal in a 900 nm range while limiting amplification in the 1060 nm range to the preset threshold.

Abstract: A laser module includes: a bottom plate of a box; the frame member being fixed to the bottom plate; a pipe member including a hollow portion PH communicating with the through hole OP of a box, the pipe member being fixed to the outer wall of the frame member; an optical fiber held on the hollow portion PH of the pipe member; and a laser element accommodated in the internal space of the box, the optical axis of the laser element being aligned with the optical axis of the optical fiber. When the bottom plate is placed on a plane, the bottom face of the pipe member is on the same face as a bottom plate portion contacting the plane.

Abstract: A Brillouin fiber laser uses a distributed feedback (DFB) fiber Bragg grating with a discrete ?-phase shift, which is offset from the physical center of the grating as a resonator. Lasing is achieved by using the SBS gain in the DFB from narrow-linewidth laser pump radiation with an optical frequency that is higher than the central pass band of the grating by an amount nominally equal to the Stokes's frequency shift, ?B. The lasing occurs at a wavelength that corresponds to the first Stokes wave. The Brillouin DFB fiber laser has a low threshold, does not require any fiber optic couplers, does not require rare-earth doping, enables connection of many DFB lasers in series, pumping using a multi-wavelength or wavelength tunable laser sources, and the laser output can be delivered along the direction of the pump propagation or in the reverse direction.

Abstract: Pulse power can be stabilized by applying spectrally narrow pulses to a laser diode during gain switching. An injection locking laser with a narrow emission bandwidth is tuned to a gain bandwidth of a laser diode to be gain switched. The injection locking emission is pulsed to provide locking pulses that are attenuated and then coupled to a laser diode. A gain switching pulse drive is applied to the laser diode in the presence of the attenuated locking pulses. The gain switched output is then stabilized with respect to pulse energy and pulse amplitude, and is suitable as a seed pulse for lasers to be used in materials processing.

Abstract: An element for the amplification of a light by stimulated emission of radiation and a method of making the same is described herein.

Abstract: The inventive concept provides optic couplers, optical fiber laser devices, and active optical modules using the same. The optic coupler may include a first optical fiber having a first core and a first cladding surrounding the first core, a second optical fiber having a second core transmitting a signal light to the first optical fiber and a third cladding surrounding the second core, third optical fibers transmitting pump-light to the first optical fiber in a direction parallel to the second optical fiber; and a connector connected between the first optical fiber and the second optical fiber, the connector extending the third optical fibers disposed around the second optical fiber toward the first optical fiber, the connector comprising a third core connected between the first core and the second core and a fifth cladding surrounding the third core.

Abstract: Embodiments of the present invention generally relate to fiber designs for wavelength tunable ultra-short pulse lasers. More specifically, embodiments of the present invention relate to systems incorporating fiber designs for higher order mode fibers capable of soliton self frequency shifting where a system comprises a first fiber for shifting the wavelength from a pump wavelength to a transfer wavelength and a second fiber for shifting the pulse from the transfer wavelength to an output wavelength. In one embodiment of the present invention, a wavelength tunable short pulse fiber laser system comprises: a pulse generator for providing a pulse having an input wavelength; a mode-converter; a first designed fiber for shifting the pulse from the input wavelength to a transfer wavelength; and a second designed fiber for shifting the pulse from the transfer wavelength to an output wavelength.

Abstract: An apparatus for generating a short-pulse laser using a temporally modulated sideband gain is provided. The apparatus includes a laser diode and an external reflector. By use of a time difference resulted by a nanosecond laser pulse signal at the external reflector, a sideband gain is obtained for generating a short-pulse picosecond laser output.

Abstract: The multi-wavelength laser is a ring laser source working at room temperature. The laser has an inner cavity disposed in an outer cavity. A pair of circulators disposed in the inner cavity is configured to assure counter-propagation of light between the inner cavity and the outer cavity. A gain-clamped semiconductor optical amplifier (GC-SOA) is formed by combining a SOA and a Fiber Fabry-Perot Tunable Filter (FFP-TF) with the circulator pair. This configuration in the laser cavity results in an improvement in terms of transient gain excursions by applying an optical feedback. This attribute of the GC-SOA enables realizing a stable multi-wavelength laser source.