The Furukawa Electric Co., Ltd.

Kousuke Kashiwagi

Yoshihiro Emori

Takeshi Takagi

Koji Kajiwara

Kazuaki Hyuga

Takashi Shigematsu

Kanji Tanaka

Tomomichi Yasuoka

Takashi Kayahara

Ryosuke Nishii

A welding method includes: disposing a workpiece formed by stacking a plurality of metal foils in an area to be irradiated with laser light that contains a plurality of beams; irradiating a surface of the workpiece with the beams of the laser light by dispersing positions of the beams such that centers of the beams do not overlap with each other within a prescribed area on the surface; melting an irradiated part of the workpiece and performing welding; and setting each of the beams to have a power density with which no hole opens in the metal foils, and setting the power density of the beams and dispersing irradiating positions to be emitted so as to form a weld pool penetrating the workpiece by the beams.

Welding method and welding apparatus

An optical fiber laser device generates laser light by using an optical amplifying fiber as an amplification medium in a laser oscillator and includes: an optical outputting fiber configured to emit laser light to an outside; a return-light-attenuating portion configured to perform an attenuation process to return light propagating through at least the optical outputting fiber in a reverse direction of the laser light; a thermal conversion unit provided at the return-light-attenuating portion and configured to convert the return light into heat; a temperature-monitoring device configured to measure an increase in a temperature, of the return-light-attenuating portion, caused by the heat converted by the thermal conversion unit; and a control unit configured to decrease or stop an output of the laser light when the temperature measured by the temperature-monitoring device becomes a predetermined threshold temperature or higher.

Optical fiber laser device

A laser unit includes: multi-mode semiconductor lasers configured to output laser lights in multi-mode; an optical multiplexer configured to multiplex and output the laser lights; a multi-mode optical fiber configured to connect the multi-mode semiconductor lasers to the optical multiplexer, and including a core portion, a cladding portion, and a coated portion; a first bending portion formed to the multi-mode optical fiber and bent with a predetermined bending length and at a predetermined first bending radius; a radiation portion formed outside the coated portion at the first bending portion, and configured to radiate heat of the multi-mode optical fiber; and a second bending portion formed to the multi-mode optical fiber between the first bending portion and the optical multiplexer and bent at a predetermined second bending radius, wherein increase in a temperature at the second bending portion is restrained by radiation from the radiation portion.

Laser unit and optical fiber laser

Growing community of inventors

Tokyo, Japan

Kousuke Kashiwagi