Mitsui Petrochemical Industries, Ltd.

Yuichiro Terashi

Yasuo Oeda

Mitsugu Terada

Ken Ohmata

Michito Uehara

Hideaki Shibata

Koichi Haruta

Kazuo Shimazaki

Shuntaro Watanabe

Kohichi Haruta

A laser beam having a circular cross section is irradiated obliquely with respect to a line vertical to a irradiating surface of material including a metal or by shaping the laser beam through an optical system of an irradiation unit, and then the laser beam having an elliptical shape is irradiated on the irradiating surface to thereby suppress weld defects such as weld cracks in weld joints of a difficult-to-weld material such as aluminum alloy.

Method and apparatus for welding material by laser beam

In order to obtain a weld bead having a good outer appearance with little splash of sputters or the like and a sufficient shearing force, there is provided a flash lamp control section for controlling flash lamps so as to generate two rectangular waves in a pulse wave form at every cycle of a pulse laser beam generated by a pulse YAG laser during the irradiation of the pulse laser beam on coated metal materials. The flash lamp control section is adapted to control a relationship between a peak power and a pulse width of a first rectangular wave and a peak power and a pulse width of a second rectangular wave in predetermined ranges. Under the control of the flash lamp control section, the pulse laser beam generated by the pulse YAG laser is irradiated to the coated metal materials thereby carry out the irradiating operation.

Pulse laser irradiation apparatus for coated metal material

A laser light, whose wavelength is to be measured, is introduced into an etalon, a concentric circular interference stripe derived from the etalon is irradiated onto a one-dimensional photodetector array and a diameter of the interference stripe is measured to measure the wavelength of the laser light. Alternatively, if a reference laser light of known wavelength is introduced into the etalon, as described above, a wavelength measurement of extremely high accuracy can be made without being affected by positional deviations of the optical system.

Method and apparatus for detecting wavelength of laser beam

A laser irradiation nozzle free from clogging, adhesion of metal oxides, directional gas blowing, and oxidation occurring on the weld; yet capable of providing sound bead morphology and a stable weld depth on a workpiece. Accordingly, the laser irradiation nozzle comprises a conical outside nozzle and a conical inside nozzle being arranged as such to give a concentric ring-shaped top, having an assist gas outlet being established between the inside and the outside nozzles, wherein, the distance h between the laser beam focal position on the workpiece and said irradiation nozzle is controlled to a predetermined value, and the ratio of the cross sectional area of the assist gas outlet being as defined between the outside and the inside nozzles to the cross sectional area of the inside concentrical ring defined by the outer diameter of said ring on the nozzle top is also controlled to a predetermined value.

Laser irradiation nozzle and laser apparatus using the same

Discharge exciting excimer laser device

Angles of inclination of the two wavelength selection elements arranged on an optical path of a laser beam source are varied to make a laser output variable. Light transmitting ranges of the two wavelength selection elements are coincided with each other so as to adjust the light wavelength bands, thereby the laser beam is narrowed without increasing its fineness.

Laser device

A gas laser apparatus having transparent laser windows provided on a laser chamber body, in which operating gases is sealed if necessary, comprising circulation means connected to the laser chamber body through an intake port and a discharge port for circulating gases within the laser chamber body and filtration means disposed in said circulation means, further comprising cutoff means for preventing the laser windows from being stained and open and closeably cutting off between the laser chamber body and the laser windows, and having a construction wherein in replacing the laser window, the cutoff means is once placed in a cutoff state, and the laser window is separated from the laser chamber body to place the laser window.

Gas laser apparatus

This invention is provided with a wavelength selecting means for uses in selectively receiving beam in compliance with each of a reference beam and a measured beam in order to simplify a correction or comparison of oscillating wavelengths in the laser device and further to improve a reliability and a controlling responsive speed.

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Sodegaura, Japan

Yuichiro Terashi