Hitachi, Ltd.

Hitachi Metals, Ltd.

Sten Helmfrid

Kimio Tatsuno

Tetsuo Andou

Shigeru Nakamura

Kenchi Ito

Kazumi Kawamoto

Masahiko Takahashi

Masayoshi Sato

Osamu Komoda

Kohei Ito

Fumio Nitanda

Tsuyoshi Miyai

Hisao Kurosawa

Koji Muraoka

Hiroshi Momiji

There is disclosed a harmonic modulation device of waveguide type including a semiconductor laser, a waveguide for generating a nonlinear optical harmonic of the semiconductor laser by keeping phase matching, means for leading an optical beam of the semiconductor laser to the waveguide, electrodes disposed on the waveguide, and means for modulating a refractive index of the waveguide electro-optically to modulate a phase matching condition and thereby modulate an intensity of the harmonic.

Short-wavelength laser light source

A short-wavelength laser having a stable output and an optical information processing system capable of high-density recording are disclosed. A solid-state laser is used as a light source, and a nonlinear optical crystal is arranged in a resonator in order to produce a short wavelength by means of a solid-state laser. The retardation of the nonlinear optical crystal is controlled by determining the length of the nonlinear optical crystal. A solid-state laser device having a stable output with the noise removed from a pumping power light source is also provided. Further, the solid-state laser device is used as a light source for the optical information processing system, and the light of irrelevant wavelengths contained in the light from the solid-state laser device are removed by a device having the ability to select wavelengths. Thus, not only a stable light source with a short wavelength but also an optical information processing system capable of high-density recording are realized.

Solid-state laser device including uniaxial laser crystal emitting

Growing community of inventors

Musashino, Japan

Sten Helmfrid