Yokogawa Electric Corporation

Ando Electric Company

Yokogawa Test & Measurement Corporation

Yokogawa Meters & Instruments Corporation

Toshikazu Yamamoto

Tsutomu Kaneko

Manabu Kojima

Toru Mori

Tohru Mori

Katsushi Ota

Akira Tanigawa

A multi-fiber connector fiber-optic measurement device identifies a polarity type and measures an optical power of a multi-fiber connector fiber-optic patch cord. The device includes: a beam splitter that splits light from the multi-fiber connector fiber-optic patch cord into a plurality of lights; a first optical sensor that receives one of the lights split by the beam splitter and outputs a first signal according to the received light; a second optical sensor that receives another of the lights split by the beam splitter and outputs a second signal according to the received light; and a signal processor that calculates the optical power based on the first signal and identifies the polarity type based on the second signal.

Multi-fiber connector fiber-optic measurement device and method

A method of testing a ribbon fiber cable is provided. The ribbon fiber cable includes optical fibers between a first end face and a second end face. End faces of the optical fibers are lined up in a single line in a line direction. The method includes: injecting light into each optical fiber at the second end face; measuring first power of the light exiting from each optical fiber at the first end face; disposing a member between the first end face and an optical sensor; injecting light into each optical fiber at the second end face; measuring second power of the light exiting from each optical fiber at the first end face; calculating a ratio of the second power to the first power; and testing an array of the optical fibers based on the ratio. Light transmittance of the member monotonically varies in the line direction.

Testing method, light receiving device, and testing system

An optical wavelength meter includes: an interferometer; a reference optical source unit with a laser configured to oscillate in a multi-longitudinal mode; and a signal processor configured to calculate a wavelength of a input beam with reference to interference fringe information of reference beam and interference fringe information of the input beam obtained from the interferometer.

Optical wavelength meter

An improvement is added to a spectroscope for performing wavelength dispersion of measured light with a wavelength dispersion element and receiving the light at a light reception element. The spectroscope has a first compound lens made up of a plurality of lenses for converting measured light into parallel light and emitting the parallel light to the wavelength dispersion element; a second compound lens made up of a plurality of lenses for gathering the measured light subjected to the wavelength dispersion in the wavelength dispersion element and causing the light reception element to receive the light; and a base for fixing the wavelength dispersion element, the first compound lens, and the second compound lens. The linear expansion coefficient of the compound focal length of the first compound lens, the linear expansion coefficient of the compound focal length of the second compound lens, and the linear expansion coefficient of a material forming the base are substantially equal.

Spectroscope

A spectroscope includes a diffraction grating having a plurality of ruled parallel lines; and a plurality of spectroscopic paths, each of which has a collimator for collimating incident light, emits the collimated light to the diffraction grating, and emits return light, which returns from the diffraction grating, through a slit provided on the path. In the spectroscope, measured light is emitted through the plurality of spectroscopic paths so as to extract light which is included in the measured light and has a predetermined wavelength; and the collimators of the spectroscopic paths are arranged so that irradiation areas of light emitted from the collimators are offset from each other at least in a direction along the ruled parallel lines. The collimators of the spectroscopic paths may be arranged so that incident angles of light emitted from the collimators coincide with each other.

Spectroscope having spectroscopic paths with individual collimators

In a wavelength calibration method, an observed spectrum of a light that has a wavelength band is obtained, wherein the light has at least an attenuated wavelength component that corresponds to at least a predetermined absorption wavelength that is included in the wavelength band. A corrected spectrum is then obtained from the observed spectrum, wherein the corrected spectrum has reduced dependencies upon the full width at half maximum of an emission band of the light and upon an intensity ripple period of the light.

Wavelength calibration method and wavelength calibration apparatus

A depolarizer includes a second birefringent plate having a thickness which continuously changes in a direction of an optical axis of the second birefringent plate; and a third birefringent plate having a thickness which continuously changes in a direction of 45 degree with respect to an optical axis of the third birefringent plate; wherein the second birefringent plate is stuck on the third birefringent plate so that a reduction direction of the thickness of the second birefringent plate and a reduction direction of the thickness of the third birefringent plate are opposite to each other.

Depolarizer and spectroscope and polychromater

A monochromator including: a concave mirror which converts incident light into parallel light and emits the parallel light, a plane diffraction grating for diffracting the parallel light emitted from the concave mirror, first reflection means which reflects first light diffracted by the plane diffraction grating and causes the diffracted light to enter the plane diffraction grating as second incident light, second reflection means which reflects second diffracted light and causes the reflected light to enter the plane diffraction grating as third incident light, and an exit slit disposed in the vicinity of a focal point such that third diffracted light is reflected by the first reflection means, to thereby enter the plane diffraction grating as fourth incident light and such that fourth diffracted light is converged at the focal point by the concave mirror, to thereby enable extraction of light having a specific wavelength.

Monochromator and optical spectrum analyzer using the same

A depolarizing plate comprising a first rectangular wedge plate that has a first crystallographic optical axis in a diagonal direction of the rectangle and which has a thickness thereof in a vertical direction vary continuously in a direction 45 degrees from said first crystallographic optical axis and a second rectangular wedge plate that has a second crystallographic optical axis in a diagonal direction of the rectangle crossing said first crystallographic optical axis at right angles and which has a thickness thereof in a vertical direction vary continuously in a direction 45 degrees from said second crystallographic optical axis, the two wedge plates being joined in such a position that said first crystallographic optical axis crosses said second crystallographic optical axis at right angles, wherein the slope formed by the joint of said wedge plates is rotated about the optical axis of an incident ray of light.

Depolarizing plate and an optical apparatus using the same

A polarization scrambler includes a Faraday element in which the thickness of a direction vertical to an optical axis changes continuously, and a magnetic field generator for generating a magnetic field in a direction of the optical axis with respect to the Faraday element.

Growing community of inventors

Tokyo, Japan

Toshikazu Yamamoto