Abstract: A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers. Apodized fiber Bragg gratings and integrated fiber polarizers are included in the cavity to assist in linearly polarizing the output of the cavity. Very short pulses with a large optical bandwidth are obtained by matching the dispersion value of the fiber Bragg grating to the inverse of the dispersion of the intra-cavity fiber.

Abstract: An intracavity resonant Fabry-Perot saturable absorber (R-FPSA) induces modelocking in a laser such as a fiber laser. An optical limiter such as a two photon absorber (TPA) can be used in conjunction with the R-FPSA, so that Q-switching is inhibited, resulting in laser output that is cw modelocked. By using both an R-FPSA and a TPA, the Q-switched modelocked behavior of a fiber laser is observed to evolve into cw modelocking.

Abstract: Double clad large mode area planar lasers or amplifiers comprising rare-earth or transition metal doped planar core regions are used to generate near-diffraction-limited optical beams of ultra-high power. The amplified light is guided in the core using different guiding mechanisms in two orthogonal axes inside the core. Waveguiding along a first long core axis is obtained substantially by gain-guiding or thermal lensing. Waveguiding along a second short core axis is obtained by index guiding. This is accomplished by surrounding the planar core region with regions of different refractive index. The long sides of the planar core region are surrounded with a depressed refractive index cladding region. The short sides of the planar core region are surrounded with a cladding region substantially index-matched to the core region. The whole structure is surrounded by an outer cladding region with a low refractive index to enable cladding pumping of the planar waveguide with high-power diode lasers.

Abstract: A modular, compact and widely tunable laser system for the efficient generation of high peak and high average power ultrashort pulses. Modularity is ensured by the implementation of interchangeable amplifier components. System compactness is ensured by employing efficient fiber amplifiers, directly or indirectly pumped by diode lasers. Peak power handling capability of the fiber amplifiers is expanded by using optimized pulse shapes, as well as dispersively broadened pulses. After amplification, the dispersively stretched pulses can be re-compressed to nearly their bandwidth limit by the implementation of another set of dispersive delay lines. To ensure a wide tunability of the whole system, Raman-shifting of the compact sources of the ultrashort pulses in conjunction with frequency-conversion in nonlinear optical crystals can be implemented, or an Anti-Stokes fiber in conjunction with fiber amplifiers and Raman-shifters are used.

Abstract: By writing non-linear chirp into fiber Bragg gratings, greater control over dispersion compensation in CPA systems is obtained, such that, for example, the dispersion profile of the fiber Bragg grating and a bulk compressor may be matched. An iterative method of writing the fiber grating can reduce the group delay ripple to very low levels; and adaptive control of the fiber grating dispersion profile can further reduce these levels, while in addition offering greater acceptable yield in the manufacture of such gratings. Fiber Bragg gratings may be designed so as to provide customized pulse shapes optimized for various end uses, such as micromachining, for example, and may also be used to counteract gain-narrowing in a downstream amplifier.

Abstract: An intracavity resonant Fabry-Perot saturable absorber (R-FPSA) induces modelocking in a laser such as a fiber laser. An optical limiter such as a two photon absorber (TPA) can be used in conjunction with the R-FPSA, so that Q-switching is inhibited, resulting in laser output that is cw modelocked. By using both an R-FPSA and a TPA, the Q-switched modelocked behavior of a fiber laser is observed to evolve into cw modelocking.

Abstract: Various embodiments include modelocked fiber laser resonators that may be coupled with optical amplifiers. An isolator may separate the laser resonator from the amplifier, although certain embodiments exclude such an isolator. A reflective optical element on one end of the resonator having a relatively low reflectivity may be employed to couple light from the laser 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 be 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 fiber Bragg grating to the inverse of the dispersion of the intra-cavity fiber. Frequency comb sources may be constructed from such modelocked fiber oscillators.

Abstract: An optical beam-shaping element is used to produce a high brightness laser beam from a diode bar or a single emitter diode, allowing for efficient coupling of the beam into an optical fiber. An embodiment of the beam-shaping element allows the construction of a quasi-monolithic beam shaper incorporating both fast axis collimation as well as beam rotation. Additional slow axis collimation of the individual emitting elements of the diode bar is also possible in one quasi-monolithic design. The beam rotation element may comprise an array of beam-inverting planar grin lenses aligned with their axes of equal refractive index at an angle of ±45° with respect to the slow axes of the emitters. Alternative embodiments comprise beam rotation elements based on Fresnel lens arrays or aspheric cylindrical lens arrays.

Abstract: A partially mirror coated parallelepipedal form is oriented to divide collimated beams along the longitudinal axes from a plurality of diode lasers arranged side-by-side along their transverse axis. The divided partial beams are subsequently recombined and arranged side-by-side along their transverse axis using the same rhomboidal form, where the parallelepipedal form and the polarization state of the collimated diode laser beams are oriented to minimize the insertion loss of the device. The side by side arranged partial beams are further coupled into an optical fiber positioned downstream of the parallelepipedal form to deliver a beam with high optical brightness.

Abstract: An optical beam shaping element is used to produce a beam of high brightness from a diode bar or a single emitter diode, allowing for efficient coupling of the beam into an optical fiber. An embodiment of the beam shaping element allows the construction of a quasi-monolithic or truly monolithic beam shaper incorporating both fast axis collimation as well as beam rotation. Additional slow axis collimation or collimation of the beam-rotated fast axes of the individual emitting elements of the diode bar is also possible in one quasi-monolithic or truly monolithic design. The beam rotation element comprises an array of beam-inverting planar grin lenses aligned with their axes of equal refractive index at an angle of ±45° with respect to the slow axes of the emitters. Alterative embodiments comprise beam rotation elements based on two planar grin lens arrays, arrays of uniaxial grin lenses, arrays of uniaxial focusing reflective optic or arrays of cylindrical Fresnel lenses.

Abstract: The invention describes techniques for the control of the spatial as well as spectral beam quality of multi-mode fiber amplification of high peak power pulses as well as using such a configuration to replace the present diode-pumped, Neodynium based sources. Perfect spatial beam-quality can be ensured by exciting the fundamental mode in the multi-mode fibers with appropriate mode-matching optics and techniques. The loss of spatial beam-quality in the multi-mode fibers along the fiber length can be minimized by using multi-mode fibers with large cladding diameters. Near diffraction-limited coherent multi-mode amplifiers can be conveniently cladding pumped, allowing for the generation of high average power. Moreover, the polarization state in the multi-mode fiber amplifiers can be preserved by implementing multi-mode fibers with stress producing regions or elliptical fiber cores These lasers find application as a general replacement of Nd:based lasers, especially Nd:YAG lasers.

Abstract: The invention provides a method of communicating between two devices performed by transmitting a series of pulses over an optical medium between the first device and the second device, the method including amplifying the pulses in an optical amplifier having a characteristic generally described by the NLSE with gain to yield parabolically shaped pulses.

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: The present invention is directed to methods and apparatuses for performing temporal scanning using ultra-short pulsewidth lasers in which only minimal (micro-scale) mechanical movement is required. The invention also relates to methods for obtaining high-accuracy timing calibration, on the order of femtoseconds. A dual laser system is disclosed in which the cavity of one or more of the lasers is dithered, by using a piezoelectric element. A Fabry-Perot etalon is used to generate a sequence of timing pulses used in conjunction with a laser beam produced by the laser having the dithered laser cavity. A correlator correlates a laser pulse from one of the lasers with the sequence of timing pulses to produce a calibrated time scale.

Abstract: The present invention is directed to methods and apparatuses for performing temporal scanning using ultra-short pulsewidth lasers in which only minimal (micro-scale) mechanical movement is required. The invention also relates to methods for obtaining high-accuracy timing calibration, on the order of femtoseconds. A dual laser system is disclosed in which the cavity of one or more of the lasers is dithered, by using a piezoelectric element. A Fabry-Perot etalon is used to generate a sequence of timing pulses used in conjunction with a laser beam produced by the laser having the dithered laser cavity. A correlator correlates a laser pulse from one of the lasers with the sequence of timing pulses to produce a calibrated time scale.

Abstract: A high gain optical parametric amplifier is implemented in a LiNbO3 waveguide fabricated by a combination of periodic electric field poling and proton exchange techniques. The device is capable of amplification in the whole transmission window of silica optical fibers with gains up to 90 dB. The high nonlinearity and resultant high gain of the waveguide-amplifier permits the use of essentially standard power (milliwatt to 10 watt) fiber laser pump sources.

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 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: An intracavity resonant Fabry-Perot saturable absorber (R-FPSA) induces modelocking in a laser such as a fiber laser. An optical limiter such as a two photon absorber (TPA) can be used in conjunction with the R-FPSA, so that Q-switching is inhibited, resulting in laser output that is cw modelocked. By using both an R-FPSA and a TPA, the Q-switched modelocked behavior of a fiber laser is observed to evolve into cw modelocking.

Abstract: An apparatus and method for delivery of high peak power pulse through an optical fiber to an optical device includes an ultrashort pulsed laser source which produces ultrashort optical pulses having high peak power. Prior to transmitting the optical pulses through a delivery optical fiber, the pulse width of the optical pulses is stretched, forming chirped optical pulses having a lower peak power. The stretched pulses are transmitted through an optical fiber which delivers the pulse to an optical device requiring ultrashort, high peak power optical pulses. The optical fiber and/or an output unit coupled to the end of the optical fiber introduces a dispersion which compensates for the dispersion introduced by the pulsed laser source and the stretcher, and delivers a recompressed optical pulse to an optical device.