Showing papers on "Fiber laser published in 2003"
01 Jan 2003
TL;DR: In this paper, high performance Quantum Cascade Lasers and their applications are discussed. But they are not suitable for use in medical applications, as shown in Figure 1 : The application of mid-IR 2-5?m Heterojunction Laser Diodes.
Abstract: Mid-Infrared 2-5 ?m Heterojunction Laser Diodes.- High Performance Quantum Cascade Lasers and Their Applications.- Mid-IR Difference Frequency Generation.- Pulsed Mid-IR Optical Parametric Oscillators.- Mid-Infrared Ultrafast and Continuous- Wave Optical Parametric Oscillators.- Mid-Infrared Fiber Lasers.- Crystalline Mid-Infrared Lasers.- Crystalline and Fiber Raman Lasers.- Narrow-Linewidth Tunable Terahertz-Wave Sources Using Nonlinear Optics.- Mid-Infrared and THz Coherent Sources Using Semiconductor-Based Materials.- Mid-Infrared Laser Applications in Spectroscopy.- Mid-IR Laser Applications in Medicine.
503 citations
TL;DR: No thermo-optical limitations are observed at the extracted /spl sim/35 W/m, therefore such fibers allow scaling to even higher powers, and single transverse mode operation is achieved with a mode-field area of 350 /spl mu/m/sup 2/.
Abstract: We report on a 2.3 m long air-clad ytterbium-doped large-mode-area photonic crystal fiber laser generating up to 80 W output power with a slope efficiency of 78%. Single transverse mode operation is achieved with a mode-field area of 350 µm2. No thermo-optical limitations are observed at the extracted ~35W/m, therefore such fibers allow scaling to even higher powers.
352 citations
TL;DR: In this article, high quality retroreflecting fiber Bragg gratings were written in standard Ge-doped telecom fiber (Corning SMF-28) after a few minutes exposure with pulsed 800-nm, 120-fs laser radiation by use of a deep-etch silica zero-order nulled phase mask optimized for 800 nm.
Abstract: High-quality retroreflecting fiber Bragg gratings were written in standard Ge-doped telecom fiber (Corning SMF-28) after a few minutes exposure with pulsed 800-nm, 120-fs laser radiation by use of a deep-etch silica zero-order nulled phase mask optimized for 800 nm. Induced index modulations of 1.9×10-3 were achieved with peak power intensities of 1.2×1013 W/cm2 without any fiber sensitization. The fiber gratings are stable and did not erase after 2 weeks at 300 °C. The primary mechanism of induced index change results from a structural modification to the fiber core.
290 citations
TL;DR: In this paper, the authors demonstrated an amplification phenomenon in a bismuth-doped silica glass at 1.3 μm with 0.8-μm excitation.
Abstract: We demonstrated an amplification phenomenon in a bismuth-doped silica glass at 1.3 μm with 0.8-μm excitation. This luminescent material is a promising candidate for use as the core-fiber material of an optical amplifier at the natural zero-dispersion wavelength (1.3 μm) of silica glass fiber.
234 citations
TL;DR: The fabrication of a Tellurite photonic crystal fiber is reported, and its waveguiding properties are demonstrated, and strong stimulated Raman scattering is observed in a fiber with an effective area Aeff=21.2microm2.
Abstract: We report the fabrication of a Tellurite photonic crystal fiber, and demonstrate its waveguiding properties. The measured minimum loss is 2.3 dB/m at a wavelength of 1055 nm. The fiber supports several modes, but in practice just the fundamental mode can be used. We have observed strong stimulated Raman scattering in a fiber with an effective area Aeff=21.2µm2, using sub-ns, ~1 µJ pump pulses at 1064 nm.
222 citations
TL;DR: A diode-pumped Nd:YAG laser with 4.6 W of linear polarized continuous-wave output power on the 4F3/2 --> 4I9/2 transitions at 946 nm is reported on.
Abstract: We report on a diode-pumped Nd:YAG laser with 4.6 W of linear polarized continuous-wave (cw) output power on the F43/2→I49/2 transitions at 946 nm. Three different crystals, cut for critical type I phase matching at room temperature, are used for the intracavity frequency doubling of the laser: 10-mm-long LiB3O5 (LBO), an 8-mm-long β-BaB2O4 (BBO), and a 10.4-mm-long BiB3O6 (BiBO) grown by FEE GmbH. Up to 2.8 W of cw output power in the blue spectral range at 473 nm has been achieved with the BiBO crystal (2.1 W with BBO and 1.5 W with LBO).
221 citations
TL;DR: In this paper, power scaling of continuous-wave fiber lasers with up to 0.5 kW output powers from a single fibre with nearly diffraction-limited beam quality without the limitation of nonlinear effects is reported.
Abstract: Power scaling of continuous-wave fibre lasers with up to 0.5 kW output powers from a single fibre with nearly diffraction-limited beam quality without the limitation of nonlinear effects is reported.
220 citations
TL;DR: An Ytterbium-doped photonic crystal fibre laser is demonstrated with a 100 microm2 core area and single transverse mode with an output efficiency of 30 % and potentially scalable to high power.
Abstract: An Ytterbium-doped photonic crystal fibre laser is demonstrated with a 100 microm2 core area and single transverse mode with an output efficiency of 30 %. Double-clad PCF laser structures are demonstrated with pump cladding NA greater than 0.8 and output power up to 3.9 W. Such lasers are potentially scalable to high power.
217 citations
TL;DR: The generation of an octave-spanning supercontinuum inside a short piece of a highly nonlinear fiber inside a stretched pulse amplifier and self-referencing detection of the carrier-envelope phase evolution with an f-to-2f interferometer is demonstrated.
Abstract: We present an improved design of an amplified Er:fiber laser system for the generation of intense femtosecond pulses. By properly controlling the influence of optical nonlinearities inside a stretched pulse amplifier, the spectrum is broadened to over 100 nm. The pulses are recompressed to 65 fs. A linearly polarized output of 110 mW is obtained at 67 MHz repetition rate. As a first application, we report the generation of an octave-spanning supercontinuum inside a short piece of a highly nonlinear fiber. Self-referencing detection of the carrier-envelope phase evolution with an f-to-2f interferometer is demonstrated.
191 citations
TL;DR: Wavelength beam combining of five ytterbium fiber lasers is demonstrated in a master-oscillator power-amplifier configuration at combined powers up to 6 W, which is equal to that of an individual fiber.
Abstract: Wavelength beam combining of five ytterbium fiber lasers is demonstrated in a master-oscillator power-amplifier configuration at combined powers up to 6 W. The combined beam profile has an M2 value of 1.14, which is equal to that of an individual fiber. Beam steering in one dimension over 140 resolvable spots is also demonstrated.
176 citations
TL;DR: An all-fiber supercontinuum source based on a passively mode-locked erbium fiber laser and a small-effective-area, germanium-doped silica fiber is presented, generating more than an octave of bandwidth.
Abstract: We present an all-fiber supercontinuum source based on a passively mode-locked erbium fiber laser and a small-effective-area, germanium-doped silica fiber. The parallels between this system and the continuum generated in microstructured fibers with 800-nm pulses are discussed, and the role of dispersion is investigated experimentally. We construct a hybrid fiber by fusion splicing lengths of different-dispersion fiber together, generating more than an octave of bandwidth.
TL;DR: This work experimentally demonstrated coherent combining of 2 and then 4 fiber lasers, and theoretically confirmed that the combining method can be scaled to a large number of lasers without decreasing the combining efficiency.
Abstract: We have experimentally demonstrated coherent combining of 2 and then 4 fiber lasers, with respectively 99% and 95% combining efficiency. The combining method investigated here is based on a multi-arm resonator of interferometric configuration. In spite of its interferometric nature, the multi-arm laser operates without significant power fluctuations, even in an unprotected environment. This occurs when the arm length difference is large enough to introduce spectral modulations of period smaller than the laser bandwidth. We have also experimentally shown that the combining method is compatible with wavelength tuning. A Mach-Zehnder Fiber Laser was tuned over a wide spectral range of 60nm Theoretically then, we confirm that the combining method can be scaled to a large number of lasers without decreasing the combining efficiency.
TL;DR: An erbium-doped, toroid-shaped microlaser fabricated on a silicon chip is described and characterized in this paper, where a silica toroidal microresonator is used to create the microcavity lasers.
Abstract: An erbium-doped, toroid-shaped microlaser fabricated on a silicon chip is described and characterized. Erbium-doped sol-gel films are applied to the surface of a silica toroidal microresonator to create the microcavity lasers. Highly confined whispering gallery modes make possible single-mode and ultralow threshold microlasers.
TL;DR: Spectral tuning of a mode-locked Yb-doped fiber laser over a 90-nm range is reported and reliable self-starting mode locking over the whole tuning range is obtained.
Abstract: Spectral tuning of a mode-locked Yb-doped fiber laser over a 90-nm range is reported. Using semiconductor saturable absorber mirrors in a fiber laser cavity incorporating a grating-pair dispersive delay line, we obtain reliable self-starting mode locking over the whole tuning range. The wide tuning range is achieved by optimization of reflection characteristics and bandgap energy of the multiple-quantum-well semiconductor saturable absorber and by proper engineering of the laser cavity.
TL;DR: In this paper, the authors reported the generation of 6 nJ chirped pulses from a mode-locked Yb fiber laser at 1.03 μm, where a linear anomalous dispersion segment suppresses wave-breaking effects of soliton-like pulse shaping at high energies.
Abstract: We report the generation of 6-nJ chirped pulses from a mode-locked Yb fiber laser at 1.03 μm . A linear anomalous-dispersion segment suppresses wave-breaking effects of solitonlike pulse shaping at high energies. The dechirped pulse duration is 50 fs, and the energy is 5 nJ. This laser produces twice the pulse energy and average power, and approximately five times the peak power, of the previous best mode-locked fiber laser. It is to our knowledge the first fiber laser that directly offers performance similar to that of solid-state lasers such as Ti:sapphire.
TL;DR: In this paper, the anomalous dispersion provided by the photonic-crystal fiber permits construction of a femtosecond fiber laser at 1 μm wavelength without prisms or diffraction gratings.
Abstract: A photonic-crystal fiber provides dispersion compensation in a soliton fiber laser. The anomalous dispersion provided by the photonic-crystal fiber permits construction of a femtosecond fiber laser at 1 μm wavelength without prisms or diffraction gratings. The laser produces ˜100-fs pulses with 1 nJ energy, and is a major step toward environmentally-stable all-fiber devices at 1 μm.
TL;DR: An advanced multimode-fiber-link model that was used to aid the development of Telecommunication Industry Association standard specifications for a next-generation 50-/spl mu/m-core laser-optimized multimode fiber is described.
Abstract: This paper describes an advanced multimode-fiber-link model that was used to aid the development of Telecommunication Industry Association standard specifications for a next-generation 50-/spl mu/m-core laser-optimized multimode fiber. The multimode-link model takes into account the interactions of the laser, the transmitter optical subassembly, and the fiber, as well as effects of connections and the receiver preamplifier. We present models for each of these components. Based on these models, we also develop an efficient and simple formalism for the calculation of the fiber transfer function and the signal at the link output in any link configuration. We demonstrate how the model may be used to develop specifications on transmitters and fibers that guarantee any desired level of performance.
Patent•
23 Dec 2003
TL;DR: An improved expandable stent for implantation in a body lumen, such as an artery, and an improved method for making it from a single length of tubing are presented in this paper.
Abstract: An improved expandable stent for implantation in a body lumen, such as an artery, and an improved method for making it from a single length of tubing. The stent (10) consists of a plurality of radially expandable cut cylindrical elements generally aligned on a common axis and interconnected by one or more interconnective elements, the elements having a rectangular cross-section from cut-to-cut. The individual radially expandable cylindrical elements are disposed in an undulating pattern. The stent is manufactured by direct laser cutting from a single metal tube using a finely focused laser beam originating from a diode pumped fiber laser (40) with an external pulse generator (44) and passing through a coaxial gas jet structure to impinge on the working surface of the tube as the linear and rotary velocity of the tube is precisely controlled. To optimize the cut, the laser parameters may be adjusted and/or the laser pulse may be shaped.
TL;DR: In this paper, the effect of varying the dispersion on the pulsed continuum and noise effects in the continuous-wave continuum has been investigated using a nonlinear Schrodinger-equation model.
Abstract: Supercontinuum generation in a highly nonlinear, dispersion-shifted fiber at 1550 nm is discussed. Spectrum generation under both pulsed and continuous-wave conditions is considered. With a few meters of highly nonlinear, dispersion-shifted fiber and a femtosecond erbium fiber laser, an octave-spanning supercontinuum is demonstrated. Kilometer lengths of nonlinear fiber pumped by a continuous-wave Raman fiber laser are shown to generate a continuum with a bandwidth greater than 247 nm. A nonlinear Schrodinger-equation model is used to investigate the effect of varying the dispersion on the pulsed continuum and noise effects in the continuous-wave continuum.
TL;DR: It is explained an observed spontaneous transition to the high-brightness, in-phase array state of a seven-core ytterbium-doped fiber laser array, which appears to be robust and scalable.
Abstract: We explain an observed spontaneous transition to the high-brightness, in-phase array state of a seven-core ytterbium-doped fiber laser array [IEEE Photonics Technol. Lett. 13, 439 (2001)]. The responsible mechanism is nonlinear refraction, and either in-phase or antiphase array modes can be selected by control of pump intensity. The phenomenon appears to be robust and scalable.
22 Jun 2003
TL;DR: In this article, the authors present the results of a high power photonic crystal fiber laser, where the well-known concepts of double-clad and large-mode-area design are transfered to an actively doped microstructured fiber.
Abstract: In this paper, we present the results of a high power photonic crystal fiber laser, where the well-known concepts of double-clad and large-mode-area design are transfered to an actively doped microstructured fiber. The double-clad design is achieved by surrounding the inner cladding (pump core) with a web of silica bridges (as thin as 390 nm and approximately 50 /spl mu/m long) which are substantially narrower than the wavelength of the guided radiation. It is concluded that air-clad microstructure ytterbium-doped large-mode-area fibers should be scalable to kW-level output powers, where nonlinearity will limit the performance.
TL;DR: An effective method for achieving a room-temperature multiwavelength erbium-doped fiber ring laser by addition of sinusoidal phase modulation in the ring cavity to prevent single-wavelength oscillation is presented.
Abstract: An effective method for achieving a room-temperature multiwavelength erbium-doped fiber ring laser is presented. Simultaneous multiwavelength lasing with 0.5-nm intervals is achieved both experimentally and theoretically by addition of sinusoidal phase modulation in the ring cavity to prevent single-wavelength oscillation.
TL;DR: In this article, a multichannel fiber filter for the multiple-wavelength generation is proposed and experimentally demonstrated using cascaded long-period fiber gratings (LPFGs).
Abstract: Multiwavelength Raman fiber lasers using intracavity tunable cascaded long-period fiber gratings (LPFGs) are discussed. The application of the cascaded LPFGs as a multichannel fiber filter for the multiple-wavelength generation is proposed and experimentally demonstrated. The characteristics of multiwavelength fiber-ring lasers can be controlled by changing the physical parameters of cascaded LPFGs such as the separation distance between the gratings, grating length, and number of gratings. The multiwavelength Raman fiber-ring laser with nine wavelength-division-multiplexing channels with 100-GHz spacing and 19 channels with 50-GHz spacing has been achieved by varying the physical parameters of cascaded LPFGs.
TL;DR: In this paper, an experimental demonstration of an all fiber CPA system based on a step-index fiber stretcher and an air-guiding photonic crystal fiber compressor is presented.
Abstract: We report on the experimental demonstration of an all fiber CPA system based on a step-index fiber stretcher and an air-guiding photonic crystal fiber compressor. The ultrafast fiber laser system producing an average power of 6.0 W with 100-fs pulses at 73 MHz, what corresponds to a peak power out of the compressor fiber of 0.82 MW. This completely fiber integrated approach has the potential to be scaled to significantly higher peak powers.
TL;DR: A novel, compact, user friendly fiber laser was used to achieve unprecedented sub-2-microm axial resolution optical coherence tomography (OCT) in nontransparent biological tissue in the 1300-nm wavelength region, demonstrating the great potential for clinical OCT applications of this stable, low-cost, and turn-on-key fiber laser.
Abstract: A novel, compact, user friendly fiber laser with a broad emission bandwidth (MenloSystems, λc=1375 nm, Δλ=470 nm, Pout=4 mW) was used to achieve unprecedented sub-2-µm axial resolution optical coherence tomography (OCT) in nontransparent biological tissue in the 1300-nm wavelength region. Fresh human skin and arterial biopsies were imaged ex vivo with ∼1.4‐µm axial and ∼3‐µm lateral resolution and 95-dB sensitivity, demonstrating the great potential for clinical OCT applications of this stable, low-cost, and turn-on-key fiber laser.
TL;DR: A mode-locked ytterbium fiber laser that generates femtosecond pulses with energies as large as 2.2 nJ is reported, which represents a 20-fold improvement in pulse energy compared with that of previously reported femTosecond Yb fiber lasers.
Abstract: We report a mode-locked ytterbium fiber laser that generates femtosecond pulses with energies as large as 2.2 nJ. This represents a 20-fold improvement in pulse energy compared with that of previously reported femtosecond Yb fiber lasers. The laser produces pulses as short as 52 fs, which are to our knowledge the shortest pulses to date from a Yb fiber laser. The laser is diode pumped by a wavelength-division multiplexing coupler, which leads to excellent stability.
TL;DR: In this article, a singlemode room-temperature cw laser emission on the 6H13/2→6H15/2 2.9 μm phonon terminated electronic transition of Dy3+ is demonstrated.
Abstract: Single-mode room-temperature cw laser emission on the 6H13/2→6H15/2 2.9 μm phonon terminated electronic transition of Dy3+ is demonstrated. The maximum output power of 0.275 W was generated at a slope efficiency of 4.5% (with respect to the absorbed pump power) when a Dy3+-doped ZBLAN fiber laser was tandem pumped with the ∼1100 nm output from a diode-cladding-pumped Yb3+-doped silica fiber laser.
TL;DR: It is demonstrated that nonlinear fiber compression is possible at unprecedented average power levels by use of a large-mode-area holey (microstructured) fiber and a passively mode-locked thin disk Yb:YAG laser operating at 1030 nm.
Abstract: We demonstrate that nonlinear fiber compression is possible at unprecedented average power levels by use of a large-mode-area holey (microstructured) fiber and a passively mode-locked thin disk Yb:YAG laser operating at 1030 nm. We broaden the optical spectrum of the 810-fs pump pulses by nonlinear propagation in the fiber and remove the resultant chirp with a dispersive prism pair to achieve 18 W of average power in 33-fs pulses with a peak power of 12 MW and a repetition rate of 34 MHz. The output beam is nearly diffraction limited and is linearly polarized.
TL;DR: Measurements of the slope efficiency and the pump power at threshold for a number of Tm3+-doped silica double-clad fiber lasers that incorporate fibers that have a range of T m3+ concentrations indicate that the cross relaxation process, 3F4, 3H6 --> 3H4,3H 4, 3 H4, has a significant effect on the efficiency of the laser despite the relatively short lifetime of the3F4 energy level.
Abstract: We present measurements of the slope efficiency and the pump power at threshold for a number of Tm3+-doped silica double-clad fiber lasers that incorporate fibers that have a range of Tm3+ concentrations. We obtain a slope efficiency for the approximately 2-microm 3H4 --> 3H6 laser transition that is greater than the Stokes efficiency limit for a Tm3+ concentration as low as 1.3 wt. %. These results indicate that the cross relaxation process, 3F4, 3H6 --> 3H4, 3H4, has a significant effect on the efficiency of the laser despite the relatively short lifetime of the 3F4 energy level. Energy migration of the excitation at the 3F4 level through the process 3F4, 3H6 --> 3H6, 3F4 may be enhancing the cross-relaxation mechanism. We also show the importance of reducing the level of clustering of the Tm3+ ion when it is doped into silica by use of appropriate amounts of Al3+ codopant. For Tm3+ concentrations of >1 wt. %, Al3+/Tm3+ concentration ratios of > 10 are recommended forreducing scattering losses, quenching the lifetime, or both.
TL;DR: The discovery of a quantization of the separation between phase-locked soliton pairs that is related to the radiation waves known as Kelly sidebands, in a passively mode-locked fiber ring laser is reported.
Abstract: We report the discovery of a quantization of the separation between phase-locked soliton pairs that is related to the radiation waves known as Kelly sidebands, in a passively mode-locked fiber ring laser. Our numerical simulations that predict this phenomenon have been confirmed by our experimental results.