Method and apparatus for sensing the wavelength of a laser beam
AssigneeKabushiki Kaisha Komatsu Seisakucho
InventorsKoichi Kajiyama, Kaoru Saito, Yasuo Itakura, Osamu Wakabayashi, Masahiko Kowaka, Tadayoshi Yamaguchi
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Abstract
A method and apparatus for sensing the wavelength of a laser beam using an optogalvano effect by atoms or molecules in plasma. Atoms or molecules in the plasma are irradiated with the laser beam. The impedance of the plasma at that time is sensed to sense whether the wavelength of the laser beam coincides with a predetermined absolute wavelength. The sensed result is used to control the wavelength of the laser beam.
Claims11
A method of sensing the wavelength of a laser beam as an object to be sensed, comprising the steps of irradiating predetermined atoms or molecules in plasma with the laser beam, sensing the impedance of the plasma at that time, and comparing the impedance with an impedance pattern measured in advance.
An apparatus for sensing the wavelength of a laser beam, comprising:
- plasma generating means for generating plasma containing predetermined atoms or molecules;
- laser irradiating means for irradiating the plasma, generated by the plasma generating means, with a laser beam as an object to be sensed;
- impedance sensing means for sensing the impedance of the plasma containing predetermined atoms or molecules;
- and
- identifying means for comparing the impedance, sensed by the impedance sensing means, with a known impedance pattern measured in advance and identifying the wavelength of the laser beam on the basis of the comparison.
An apparatus for sensing the wavelength of a laser beam, comprising:
- plasma generating means for generating plasma containing predetermined atoms or molecules;
- laser irradiating means for irradiating the plasma, generated by the plasma generating means, with part of the laser beam output from a laser oscillator;
- impedance sensing means for sensing the impedance of the plasma containing predetermined atoms or molecules;
- identifying means for comparing the impedance, sensed by the impedance sensing means, with a known impedance pattern measured in advance and identifying the wavelength of the laser beam output from the laser oscillator on the basis of the comparison;
- and
- control means for controlling the wavelength of the laser beam output from the laser oscillator on the basis of the wavelength identified by the identifying means.
An apparatus for sensing the wavelength of a laser beam, comprising:
- plasma generating means for generating plasma containing predetermined atoms or molecules;
- laser irradiating means for irradiating the plasma, generated by the plasma generating means, with part of the laser beam output from a laser oscillator;
- impedance sensing means for sensing the impedance of the plasma containing predetermined atoms or molecules;
- identifying means for comparing the impedance, sensed by the impedance sensing means, with a known impedance pattern measured in advance and identifying the wavelength of the laser beam output from the laser oscillator on the basis of the comparison;
- first control means for controlling the wavelength of the laser beam output from the laser oscillator on the basis of the wavelength identified by the identifying means;
- wavelength sensing means for sensing the wavelength of the laser beam output from the laser oscillator;
- and
- second control means for further controlling the wavelength of the laser beam output from the laser oscillator on the basis of the output from the wavelength sensing means.
Dependencies are inferred from the claim text.