Abstract: The invention relates to a light source apparatus having a structure for effectively suppressing a negative effect due to a nonlinear effect generated in propagation of an amplifying light, and realizing a stable operation. In the light source apparatus, light amplified in an optical amplifier fiber is emitted to the outside of the apparatus through an optical output fiber whose one end is connected to an output connecter. At this time, a part of Raman scattered light, generated in the optical output fiber, propagates toward an pumping light source through the optical amplifier fiber from the optical output fiber. An optical component having an insertion loss spectrum that attenuates the Raman scattered light but allows pumping light or light to be amplified to transmit therethrough, is provided on a propagation path of the Raman scattered light, due to the light component, the intensity of the Roman scattered light reaching the pumping light source is effectively reduced.

Abstract: The present invention relates to a laser light source having a structure for narrowing a wavelength bandwidth of output light. The laser light source comprises, at least, a laser resonator, a pumping light source, an optical path switch device, a diffraction grating, and a total reflection mirror. The laser resonator has a light amplifying fiber for output of emission light arranged on a resonance optical path thereof. The optical path switch device has a first port and a second port on the resonance optical path of the laser resonator. The diffraction grating spectrally separates the emission light outputted from the second port. The total reflection mirror reflects a specific wavelength component out of wavelength components spectrally separated by the diffraction grating, so as to feed the specific wavelength component back to the second port.

Abstract: The present invention relates to a laser processing apparatus and the like having a structure for implementing at the same time both an efficient laser processing in the place where a laser beam is difficult to reach and a laser processing without damages in the place where the laser beam is easy to reach. This laser processing apparatus comprises a laser light source, an irradiation optical system applying a laser beam to an object while scanning the laser beam, a photo-detector detecting the laser beam applied from the irradiation optical system, and a control section of making switching between a continuous oscillation and a pulse oscillation of the laser beam at the laser light source.

Abstract: The present invention relates to an optical amplifier module, or the like, having a structure for enabling effective suppression of photodarkening and efficient optical amplification. The optical amplifier module comprises a first optical amplification waveguide which is comprised of a phosphate glass as a main component and includes a ytterbium-doped first optical waveguide region, a second optical amplification waveguide which is optically coupled to the first optical amplification waveguide and includes a ytterbium-doped second optical waveguide region which is co-doped with aluminum, and pumping light source units which supply pumping light respectively to the first optical amplification waveguide and the second optical amplification waveguide. The light to be amplified, having inputted to the first optical amplification waveguide, is amplified only once by means of the pumping light, in each of the first optical amplification waveguide and the second optical amplification waveguide.

Abstract: The fiber laser apparatus comprises an amplifying section for amplifying seed light by cladding-pumping, and has a structure for further using a residual component of pumping light for cladding-pumping in order to heat the object. A guiding optical fiber is provided between an amplifying optical fiber of the amplifying section and an output optical system converging the single-mode amplified seed light on the object, the guiding optical fiber serving to increase the degree of freedom in arranging the output optical system. The guiding optical fiber has a structure enabling the single-mode propagation of the amplified seed light outputted from the amplifying optical fiber and multimode propagation of the residual pumping light. Because the object is irradiated with the converged amplified seed light, while being heated with the residual pumping light outputted from the output optical system, even an object with a complex shape can be subjected to efficient laser processing.

Abstract: The present invention relates to a laser apparatus capable of supplying laser beams from each of plural beam emitting ends constituting laser beam output ports, and realizes the overall low power consumption and low non-linearization. The laser apparatus comprises a seed light source, beam emitting ends, an intermediate optical amplifier, an optical branching device, and final-stage optical amplifiers. The number of beam emitting ends is greater than the number of seed light sources, and the final-stage optical amplifiers and the beam emitting ends correspond to each other one-on-one. The optical branching device includes an input port associated to the seed light source and plural output ports associated to the respective beam emitting ends so as to constitute a part of the light paths between the seed light source and the beam emitting ends.

Abstract: The present invention relates to an optical amplification module having a construction which effectively suppresses photodarkening, and to a laser light source including the same. The laser light source comprises a light source for outputting light to be amplified, and an optical amplification module. The optical amplification module comprises two types of optical amplification media having different rare earth element concentrations, and a pumping light source. The low concentration medium and the high concentration medium are disposed in the propagation direction of pumping light such that the population inversion of the low concentration medium is higher than that of the high concentration medium.

Abstract: The present invention relates to a laser processing method and the like which use no wavelength conversion technique by nonlinear optical crystals when selectively removing an insulating layer of a printed board, while employing only one wavelength throughout the entire removal processing. A laser processing apparatus (1), preferably used in the laser processing method, has a MOPA structure and comprises a seed light source (100), a YbDF (110), a bandpass filter (120), a YbDF (130), a bandpass filter (140), a YbDF (150), a YbDF (160), and so forth.

Abstract: The present invention relates to a light source apparatus having a structure to enable a short pulse optical output with high pulse energy or a high pulse peak equivalent to that of a Q switch laser light source. The light source apparatus comprises a seed light source, a pre-stage optical amplifier, a subsequent-stage optical amplifier, and a control section. After the pulse light outputted from the seed light source is amplified by the pre-stage optical amplifier, the pulse light is amplified further by the subsequent-stage optical amplifier. In the subsequent-stage optical amplifier, a ring-type resonator is constituted by an optical coupler, an optical coupler, an optical amplification waveguide, an optical isolator, an optical coupler, an optical waveguide, a lens, a Q switch, a lens, and an optical waveguide that are disposed sequentially on the propagation path of the pulse light.

Abstract: The present invention relates to fluorescent glass which is easily put into practical use, and optical elements including the same. In one aspect, the fluorescent glass is comprised of silica-based glass containing Bi as a dopant, and adapted to generate fluorescence in response to pumping light in a wavelength band of 980 nm incident thereon. In another aspect, the fluorescent glass contains at least one species of transition metal as a dopant, and exhibits a 980-nm band absorption spectrum having a full width at half maximum exceeding 10 nm. In still another aspect, the fluorescent glass is comprised of silica-based glass containing at least one species of transition element as a dopant, and exhibits a fluorescence spectrum with a peak intensity fluctuating within a range of ?1 dB or more but 1 dB or less with respect to pumping light having a fixed intensity in a state set to a temperature of ?5° C. or more but 65° C. or less.

Abstract: The present invention relates to a laser processing method and laser processing apparatus for enabling improvement and maintenance of homogenization of a beam intensity distribution in an irradiated region. The laser processing apparatus comprises, at least, an ASE light generation section for emitting ASE light, and a homogenizer for splitting the ASE light into multiple beams. The ASE generation section for emitting the ASE light as processing laser light is provided, and whereby the deterioration of homogenization due to inter-beam interference is suppressed. The homogenization of beam intensity distribution is improved by locating a condenser lens relative to an object such that the object is shifted from a focus position of the condenser lens in the homogenizer, by intentionally deteriorating a beam quality M2 of the ASE light itself emitted from the ASE light generation section to about 2 to 10, or by a combination of these, in laser processing.

Abstract: The present invention discloses a laser light source for implementing pulsed oscillation of laser light, which has a laser cavity in which a laser medium for generating emitted light with supply of excitation energy is placed on a resonance path; an excitation device for continuously supplying excitation energy to the laser medium; a monitor part for monitoring a power of light extracted at a middle point of the path of the cavity from the laser medium in accordance with the supply of the excitation energy by the excitation device; a Q-switch for modulating a cavity loss of the laser cavity; and a control part for performing such control as to stabilize a peak power or an energy of laser light pulses outputted in a state in which the cavity loss of the laser cavity is set at a second predetermined loss for oscillation of high-power pulses, based on the power of the emitted light monitored by the monitor part in a state in which the cavity loss of the laser cavity is set at a first predetermined loss for non-o

Abstract: The present invention relates to an optically active device comprising a plurality of stages of optical amplifying sections cascaded on an input light propagation path, and a structure for effectively preventing an upstream pumping light source from being destroyed by ASE light propagating in a direction opposite to the input light. The optically active device comprises, at least, a front-stage optical amplifying section and a rear-stage optical amplifying section which are adjacent to each other on the input light propagation path. Each of the front-stage optical amplifying section and rear-stage optical amplifying section includes an amplification fiber doped with ytterbium as an optically active material and a pumping light source for supplying the amplification optical fiber with pumping light in the band of 0.98 ?m for pumping the optically active material.

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: The present invention relates to a laser light source having a structure for effectively suppressing generation of an optical surge upon a restart after suspension of output of pulsed light. The laser light source comprises a first light source outputting light with a first wavelength as pulsed light, a second light source outputting light with a second wavelength different from the first wavelength, an optical amplification fiber as an optical amplifier amplifying the pulsed light outputted from the first light source and the light outputted from the second light source, and a control unit controlling the output of the light from the second light source in accordance with the light output from the first light source. The first light source has an ON state in which repetitive output of the pulsed light on a fixed cycle starts and continues, and an OFF state in which the output of the pulsed light is suspended during a duration of not less than the fixed cycle.

Abstract: The present invention relates to a laser light source having a structure for narrowing a wavelength bandwidth of output light. The laser light source comprises, at least, a laser resonator, a pumping light source, an optical path switch device, a diffraction grating, and a total reflection mirror. The laser resonator has a light amplifying fiber for output of emission light arranged on a resonance optical path thereof. The optical path switch device has a first port and a second port on the resonance optical path of the laser resonator. The diffraction grating spectrally separates the emission light outputted from the second port. The total reflection mirror reflects a specific wavelength component out of wavelength components spectrally separated by the diffraction grating, so as to feed the specific wavelength component back to the second port.

Abstract: The present invention relates to an optical amplifier and the like having a flatter gain spectrum in the wavelength band of 1490 nm to 1520 nm than before. The optical amplifier according to the present invention comprises an Er-doped optical waveguide and a Tm-doped optical waveguide having gain spectra difference from each other in the wavelength band. The signal light entered through the input end is first amplified by the Er-doped optical waveguide, and thereafter is amplified by the Tm-doped optical waveguide. The gain deviation of the amplified signal light, which has been amplified in the Er- and Tm-doped optical waveguides and outputted through the output end, can be reduced over the wavelength band.

Abstract: The present invention relates to a laser light source having a structure that has high durability to support high power output. The laser light source is an optical device that pulse-oscillates laser light and has a resonator, a rare earth element doped fiber, pumping means, Q switch means, and a condensing lens. The resonator forms a resonance optical path. A fiber is inserted on the resonance optical path and outputs radiation light by supply of pumping energy. The pumping means continuously supplies pumping energy to the fiber. The Q switch means modulates resonator loss of the resonator. The condensing lens condenses the radiation light whose spot size has been expanded and which propagates from the fiber to the Q switch means.

Abstract: The present invention relates to a laser marking method which is capable of changing the grey level of a marking even in the case of a high processing speed. The laser marking method forms a marking pattern on a marking object by irradiating the marking object with pulsed light oscillated from a pulsed light source of a MOPA structure in which a semiconductor laser outputting directly-modulated pulsed light is used as a seed light source. At this time, the pulse duration of the pulsed light is changed in order to change a gray level of the marking pattern to be formed. In this way, a peak power of the pulsed light is changed by changing the pulse duration, so that it is possible to positively change the gray level of the marking pattern without changing the processing speed.

Abstract: The present invention relates to a surface modification method allowing the surface of a subject to be more effectively modified. In a pulsed-laser device suitable for use in this surface modification method, a semiconductor laser light source and a modulator constitute a seed light source. The seed light output from the seed light source is amplified by fibers for optical amplification, and the amplified light constitutes output from the pulsed-laser device. The pulsed-laser device allows the pulse width and repetition frequency of the output pulsed-laser light to be varied independently of each other. The pulse width of the pulsed-laser light output from the pulsed-laser device is preferably not more than 10 ns, and the repetition frequency is preferably at least 50 kHz.