Sumitomo Osaka Cement Co., Ltd.

Nec Corporation

Sumitomo Cement Co., Ltd.

Hitoshi Oguri

Takashi Nakamura

Takaaki Ogata

Tokutaka Hara

Tadashi Koga

Masahito Mure

Miki Yatsuki

Motoya Hirota

The present invention realizes an enhancement of a fabrication yield and a reduction of a size regarding an optical modulator or an optical device including polarization beam combining means. An optical modulator of the present invention (1) includes: first and second optical modulators (LN optical modulators () to ()) that are formed on a substrate; a polarization beam rotating unit () that rotates at least one polarization beam of modulated light beams modulated by the first and second optical modulators; and a polarization beam combining element () that is disposed outside the substrate and that combines the polarization beams of the modulated light of which the polarization beams are rotated by the polarization beam rotating unit ().

Optical modulator

A laser beam generating apparatus includes a semiconductor element and a second harmonic generating element that performs a wavelength conversion on fundamental light emitted from the semiconductor element, the laser beam generating apparatus is an external resonance-type laser diode that has an external resonator structure and emits a transversal single mode laser beam, and the second harmonic generating element is a waveguide-type second harmonic generating element that includes a single mode waveguide.

Apparatus and method of generating laser beam

An optical receiver board wherein, a signal light is amplified in an optical fiber amplifier. The amplified signal light is supplied to an electrically driven optical wavelength-tuning filter such as a multi-layered film interference filter, through which a signal light of a predetermined wavelength bandwidth is transmitted. The transmitted signal light is divided into first and second signal lights. The first signal light is converted to an electric signal which is amplified by an equalizing amplifier, and an amplified electric signal is supplied to a discrimination circuit, in which an information electric signal is generated by using a timing signal. The optical wavelength-tuning filter comprises a rotation actuator having a magnet-rotating portion and control coils, and an optical filter member fixed to the top of the magnet-rotating portion. In operation, the wavelength-tuning filter is swept by a sweep signal, so that an electric signal converted from a signal light transmitted through the optical wavelength-tuning filter becomes a predetermined value, and the tracking control is carried out to maximize power of the transmitted signal light. The inclination angle of the optical filter member is changed by controlling currents flowing through the control coils of the actuator, so that a transmission center wavelength of the signal light is adjusted.

Optical receiver board, optical wavelength-tuning filter module used for

Chrysoberyl single crystal and method of producing the same

Growing community of inventors

Funabashi, Japan

Hitoshi Oguri