Abstract: The present invention relates to an optical module which is capable of amplifying light to be amplified to high power and which has a structure for effectively reducing influences of damage to other optical parts, and heat generation. The optical module includes a fiber unit constituted by an optical coupler, an amplification optical fiber, and an absorption optical fiber. Each of the amplification optical fiber and the absorption optical fiber has a core, a first cladding, a second cladding, and a third cladding. Further, each of the fibers allows the light to be amplified to propagate in a single mode in each of the cores, and allows pumping light to propagate in a multimode in the core, the first cladding, and the second cladding. The core of the amplification optical fiber is doped with an amplification dopant for amplifying the light to be amplified. The second cladding of the absorption optical fiber is doped with an absorption dopant for absorbing the pumping light.

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 laser processing apparatus having a structure for effectively processing of objects by condensing a laser beam, and a laser processing method. A laser processing apparatus comprises a common mount surface on which plural objects are disposed in an array, a light source, a lens the reflection direction of which is changeable, and a condensing direction modifier. A laser beam from the light source arrives at the lens through a galvano-mirror. Herein, the galvano-mirror is arranged such that the reflection position thereof agrees with the front focal position of the lens. As the galvano-mirror reflects a laser beam toward the lens while the reflection direction is changed, the arriving position of the laser beam is scanned on the entrance surface of the lens. The condensing direction modifier modifies, according to the irradiation position of the laser beam arrived from the lens, an exit direction of the laser beam.

Abstract: The present invention relates to a method of measuring backward light, which is constructed for checking, prior to laser processing, backward light that propagates backward through an isolator included in a laser processing apparatus. The present invention also relates to a laser processing method and the like. A laser processing apparatus has an optical head provided with a laser light source part, light guide, and isolator. The optical head has an emitting optical system, irradiation optical system, and light collecting optical system. The method of measuring backward light uses a photodetector to detect, from reference light introduced from a measurement light source into the optical head, the power of an optical component that has passed through the isolator, while changing the position of the measurement light source.

Abstract: The present invention relates to an optical amplifier provided with a plurality of optically cascade-connected amplification units and also with a structure for enabling suppression of transient gain variations as a whole. Each of the plurality of amplification units in the optical amplifier has a pumping light source and an amplifying optical fiber, and at least one selected from the plurality of amplification units includes a timing adjustment system for temporally moving back or forth the variation timing of pumping light power accompanying the signal light power variation due to the variation of the number of signal channels, with respect to the variation timing of signal light power at a light incident end of the amplifying optical fiber contained in the own amplification unit.

Abstract: The present invention relates to a laser processing method that makes it possible to effectively suppress the generation of surface irregularities on the surface of a plastic member where a metal member and a plastic member are joined together. In the laser processing method, a plurality of laser beams are irradiated from different directions so as to focus on the vicinity of an interface between the metal member and the plastic member, which are in contact with one another. The power densities of the respective laser beams at this time are set to a level not more than a level, at which the exposed surface of the plastic member on the side opposite to the interface between the metal member and the plastic member, does not melt. As a result of this, air bubbles or the like are not generated in the vicinity of the exposed surface of the plastic member, and the generation of surface roughness on the exposed surface of the plastic member is effectively suppressed.

Abstract: The present invention relates to a laser processing method and the like provided with a structure for enabling realization of both preferable processing of locations not easily reached by laser light and effective inhibition of damage caused to locations easily reached by laser light during laser processing. Radiation optics scan locations irradiated with laser light from a laser light source while radiating laser light onto a plurality of objects arranged on a stage and the periphery thereof from a direction perpendicular to the stage. On the stage reflecting members are respectively arranged adjacent to the plurality of objects. The reflecting members reflect laser light radiated from the radiation optics towards lateral surfaces of the objects. Since laser light reflected by the reflecting members is radiated onto the lateral surfaces of the objects, laser light also reaches the lateral surfaces of the objects not easily reached by laser light without having to increase the intensity of the laser light.

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 an optical module that has a structure for protecting a pumping light source at a low cost. The optical module comprises an amplification optical fiber, an optical coupler, a pumping light source, a delay optical fiber, a seed light source, an optical fiber, a photodetector, an optical fiber, an optical isolator, an optical isolator, and a control section. Through the insertion of the delay optical fiber between the pumping light source and the optical coupler, the timing of the output control of the pumping light source which is carried out after the photodetector detects return light leads the timing with which the return light enters the pumping light source. Hence, the time with which the return light enters the pumping light source is shortened and the accumulative damage time of the pumping light source is reduced.

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 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 a light source apparatus or the like provided with a structure that can block reflected return light also when an emitting end side of an optical isolator is a space. The light source apparatus comprises a light source section, a guide section, and an optical module. The optical module includes a collimator, an optical isolator, and an oblique-beam blocking section. The collimator outputs collimated light with a predetermined beam diameter as a forward propagating beam. The optical isolator is a polarization-independent optical isolator that introduces the collimated light from a first end and outputs this collimated light from a second end.

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 an optical module which is capable of amplifying light to be amplified to high power and which has a structure for effectively reducing influences of damage to other optical parts, and heat generation. The optical module includes a fiber unit constituted by an optical coupler, an amplification optical fiber, and an absorption optical fiber. Each of the amplification optical fiber and the absorption optical fiber has a core, a first cladding, a second cladding, and a third cladding. Further, each of the fibers allows the light to be amplified to propagate in a single mode in each of the cores, and allows pumping light to propagate in a multimode in the core, the first cladding, and the second cladding. The core of the amplification optical fiber is doped with an amplification dopant for amplifying the light to be amplified. The second cladding of the absorption optical fiber is doped with an absorption dopant for absorbing the pumping light.

Abstract: The present invention relates to a laser processing method and the like having a structure for making it possible to process an object to be processed in various ways while accurately adjusting the installation state of the object. The method irradiates the object with plural adjustment laser light beams that are set in a specific positional relationship against a converging point of processing laser light beam, and adjusts the state of installation of the object while monitoring irradiation areas of the adjustment laser light beams on the surface of the object. Each irradiation directions of adjustment laser light beams is different from that of the processing laser light beam. By reflecting the irradiation condition of the adjustment laser light beam and monitored information of the irradiation areas in positional adjustment of the object, the installation state of the object can be adjusted in accordance with various kinds of processing.

Abstract: The present invention relates to an optical module that has a structure for protecting a pumping light source at a low cost. The optical module comprises an amplification optical fiber, an optical coupler, a pumping light source, a delay optical fiber, a seed light source, an optical fiber, a photodetector, an optical fiber, an optical isolator, an optical isolator, and a control section. Through the insertion of the delay optical fiber between the pumping light source and the optical coupler, the timing of the output control of the pumping light source which is carried out after the photodetector detects return light leads the timing with which the return light enters the pumping light source. Hence, the time with which the return light enters the pumping light source is shortened and the accumulative damage time of the pumping light source is reduced.

Abstract: The invention relates to a fiber laser apparatus having a structure that enables efficient laser processing for an object and to a laser processing method. 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. In particular, 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.

Abstract: The present invention relates to a fouling removing method which removes a fouling, comprised of a chemical compound containing carbon, on an object surface by laser light irradiation. The fouling removing method irradiates the fouling on the object surface with laser light while blowing a supporting gas on this area. This structure allows the supporting gas and a fouling material to react with each other when burning the fouling by laser irradiation, so as to generate a carbon-containing gas, and the supporting gas to blow away carbonized residues generated on the object surface. This drastically reduces the carbonized residues on the exposed surface of the object having removed the fouling.

Abstract: The present invention relates to a method and apparatus having a structure that enables laser processing of an object even when the object has a surface formed with irregularities. The laser processing method irradiates objects, each having a cylindrical form extending in a first direction, with laser light. Here, the objects are arranged on a first plane along a second direction orthogonal to the first direction. The arranged objects are irradiated with first and second laser light beams in irradiation directions different from each other to the first plane. At least during when the first and second irradiation light beams are respectively emitted, irradiation positions of the first and second laser light beams to the first plane are relatively moved.

Abstract: The present invention relates to an optical amplifier provided with a plurality of optically cascade-connected amplification units and also with a structure for enabling suppression of transient gain variations as a whole. Each of the plurality of amplification units in the optical amplifier has a pumping light source and an amplifying optical fiber, and at least one selected from the plurality of amplification units includes a timing adjustment system for temporally moving back or forth the variation timing of pumping light power accompanying the signal light power variation due to the variation of the number of signal channels, with respect to the variation timing of signal light power at a light incident end of the amplifying optical fiber contained in the own amplification unit.