Patents by Inventor Hirofumi Aota
Hirofumi Aota has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20140078508Abstract: An optical module includes an interferometer having at least two optical exit ends; an optoelectronic converting element having at least two light-receiving surfaces; and plural lenses that are disposed between the interferometer and the optoelectronic converting element, that optically couple light exiting from the interferometer with two light-receiving surfaces of the optoelectronic converting element. The lenses are disposed having focal distances and a distance therebetween that reduce positional displacement on the two light-receiving surfaces of the optoelectronic converting element, the positional displacement being generated at each of the two optical exit ends of the interferometer.Type: ApplicationFiled: November 20, 2013Publication date: March 20, 2014Applicant: Fujitsu Optical Components LimitedInventor: Hirofumi AOTA
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Patent number: 8285088Abstract: A wavelength selective switch for suppressing degradation of pass band characteristics when the temperature rises. The wavelength selective switch includes a spectroscopic element for separating input light and providing angular dispersion depending on wavelengths, a collective lens for gathering light output from the spectroscopic element, and a movable reflection block which includes a plurality of mirrors arranged in the direction of angular dispersion made by the spectroscopic element, changes the angles of the mirrors in a direction differing from the direction of angular dispersion, and reflects the light coming from the collective lens. The collective lens is fixed at one end with respect to the direction of angular dispersion, expands with heat in a direction in which it is not fixed when the temperature rises, and outputs the light in a direction opposite to the direction in which the angle of light output from the spectroscopic element changes.Type: GrantFiled: February 5, 2008Date of Patent: October 9, 2012Assignee: Fujitsu LimitedInventors: Hirofumi Aota, Kohei Shibata, Tsuyoshi Yamamoto
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Patent number: 8243372Abstract: An optical apparatus includes a collimation optical member for collimating and outputting input light, a condensing optical member for condensing light from the collimation optical member and a light blocking mask member provided at a place on an optical path of the input light for light blocking part of the input light, and enhances the degree of freedom in design of an optical system.Type: GrantFiled: January 21, 2009Date of Patent: August 14, 2012Assignee: Fujitsu LimitedInventors: Hirofumi Aota, Kohei Shibata, Tamotsu Akashi, Tsuyoshi Yamamoto
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Patent number: 8165470Abstract: In a wavelength selecting switch, light output from an input port of an input/output optical system is angularly dispersed according to a wavelength thereof, with a spectral element. Then the lights of respective wavelengths are collected by a light collecting optical system and reflected with a corresponding reflecting mirror of a mirror section. The reflected light corresponding to the angle of the reflecting mirror, is input to an output port at an output destination of the input/output optical system. The respective output ports of the input/output optical system each have a lens coupled to an end face of an optical fiber, and the lens has a structure where a focal length of a first region corresponding to inside a variable range of attenuation is different from a focal length of a second region corresponding to outside the variable range.Type: GrantFiled: April 30, 2009Date of Patent: April 24, 2012Assignee: Fujitsu LimitedInventors: Hirofumi Aota, Tamotsu Akashi, Tsuyoshi Yamamoto
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Patent number: 7982957Abstract: In an optical apparatus according to the present invention, the lens thicknesses and curvature radiuses of respective first lenses are optimized so that beam waist positions of optical beams emitted from the respective first lenses of a lens array are independently changed according to aberration of a second lens, and the focal position deviation due to the aberration of the second lens is cancelled by a difference between the beam waist positions, which is given on the lens array side. As a result, it is possible to suppress, at a low cost, variations in focal positions of the optical beams which are emitted from respective ports of the lens array to be condensed by the common lens.Type: GrantFiled: July 11, 2007Date of Patent: July 19, 2011Assignee: Fujitsu LimitedInventors: Shinichi Takeuchi, Tamotsu Akashi, Hirofumi Aota
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Patent number: 7787721Abstract: The MEMS mirror, which has a reflective surface whose angle is variably changed, is provided with a portion whose reflectance is lowered than that of a center portion. The portion is provided in at least part of ends on a predetermined side of the MEMS mirror. As a result, a diffraction influence of light reflected by the end surfaces can be reduced at the time of angle change of the MEMS mirror.Type: GrantFiled: January 28, 2005Date of Patent: August 31, 2010Assignee: Fujitsu LimitedInventors: Hirofumi Aota, Tamotsu Akashi
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Patent number: 7706049Abstract: The present mirror device for suppressing PDL on the assumption of multiple modes of angles of input light and output light to movable mirrors with respect to the crystal axis of a crystal member at the time light passes through the crystal member. The mirror device includes a mirror system 2 and a flat-shaped crystal member 3 which is arranged in such a manner that a first angle is not larger than a second angle. The crystal member is constructed in such a manner that a third angle is substantially equal to a half of a fourth angle.Type: GrantFiled: February 20, 2008Date of Patent: April 27, 2010Assignee: Fujitsu LimitedInventors: Hirofumi Aota, Kohei Shibata, Tamotsu Akashi, Tsuyoshi Yamamoto
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Publication number: 20100021167Abstract: In a wavelength selecting switch, light output from an input port of an input/output optical system is angularly dispersed according to a wavelength thereof, with a spectral element. Then the lights of respective wavelengths are collected by a light collecting optical system and reflected with a corresponding reflecting mirror of a mirror section. The reflected light corresponding to the angle of the reflecting mirror, is input to an output port at an output destination of the input/output optical system. The respective output ports of the input/output optical system each have a lens coupled to an end face of an optical fiber, and the lens has a structure where a focal length of a first region corresponding to inside a variable range of attenuation is different from a focal length of a second region corresponding to outside the variable range.Type: ApplicationFiled: April 30, 2009Publication date: January 28, 2010Applicant: FUJITSU LIMITEDInventors: Hirofumi Aota, Tamotsu Akashi, Tsuyoshi Yamamoto
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Patent number: 7653273Abstract: The optical switch includes: a spectroscopic device which separates wavelength division multiplexed (WDM) light into its component wavelengths; and a plurality of movable reflectors, arranged in a spectral direction at different intervals, for reflecting light of an individual component wavelength separated by said spectroscopic device. With this optical switch, deterioration of the characteristic of the pass band is avoided, so that the pass band characteristic is increased.Type: GrantFiled: January 24, 2005Date of Patent: January 26, 2010Assignee: Fujitsu LimitedInventors: Shinji Yamashita, Tsuyoshi Yamamoto, Tamotsu Akashi, Kohei Shibata, Hirofumi Aota, Osamu Tsuboi
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Patent number: 7636503Abstract: A wavelength selective switch of the present invention angularly disperses lights output from a plurality of input ports of an input and output optical system, to an X-direction, according to wavelength, by a diffraction grating to supply the dispersed lights to a condenser lens. The condenser lens is arranged so that a center axis thereof is shifted to the X-direction relative to an axis passing through the center of spreading angle to the X-direction of output beams from the diffraction grating, and accordingly, at a non-operating time, the light of each wavelength passed through the condenser lens is incident on each movable mirror being tilted by an offset angle corresponding to a shift amount of the condenser lens. As a result, it becomes possible to block the connection between an input side and an output side at the non-operating time without degrading the performance at an operating time.Type: GrantFiled: March 11, 2008Date of Patent: December 22, 2009Assignee: Fujitsu LimitedInventors: Tsuyoshi Yamamoto, Tamotsu Akashi, Kohei Shibata, Hirofumi Aota, Shinji Yamashita
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Publication number: 20090290223Abstract: An optical apparatus includes a collimation optical member for collimating and outputting input light, a condensing optical member for condensing light from the collimation optical member and a light blocking mask member provided at a place on an optical path of the input light for light blocking part of the input light, and enhances the degree of freedom in design of an optical system.Type: ApplicationFiled: January 21, 2009Publication date: November 26, 2009Applicant: Fujitsu LimitedInventors: Hirofumi AOTA, Kohei Shibata, Tamotsu Akashi, Tsuyoshi Yamamoto
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Patent number: 7613370Abstract: An optical switch includes an input port into which a multiplexed optical signal is input; a dispersing unit that, according to wavelength, disperses the multiplexed optical signal into a plurality of optical signals that are each dispersed in a unique direction; a converging unit that converges the dispersed optical signals; plural mirrors that are arrayed forming a single row in a plane and reflecting the converged optical signals, respectively; and plural output ports through which the reflected optical signals are output. Each of the mirrors has a concave reflective surface that is in the plane and of a predetermined curvature about an axis parallel to the plane.Type: GrantFiled: February 29, 2008Date of Patent: November 3, 2009Assignee: Fujitsu LimitedInventors: Kohei Shibata, Hirofumi Aota, Tamotsu Akashi, Toshiya Kishida, Hiroyuki Furukawa
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Patent number: 7580599Abstract: An optical switch switches ports through which a beam is input and output and includes an optical system through which the beam passes; a movable reflector that is enclosed in a casing and reflects, at a variable angle, the beam that has passed through the optical system; and a transmissive window that is disposed in the casing at a position through which the beam passes, is made of a uniaxial crystal, and obtains a phase difference with respect to the beam passing therethrough having a wavelength ?. The phase difference is ?/4 times a positive odd integer and results from a setting of an orientation of a crystal axis and a thickness of the transmissive window.Type: GrantFiled: May 23, 2008Date of Patent: August 25, 2009Assignee: Fujitsu LimitedInventors: Hirofumi Aota, Kohei Shibata, Tamotsu Akashi, Tsuyoshi Yamamoto, Naoki Hashimoto
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Publication number: 20090135488Abstract: An optical device and a wavelength selector switch are provided. The optical device includes a diffraction grating having first and second planes and first and second reflecting planes located on a first plane side of the diffraction grating. In the optical device, light input to the second plane of the diffraction grating is diffracted, and then an optical path of the diffracted light is re-input to the first plane of the diffraction grating newly via the first and the second reflecting planes.Type: ApplicationFiled: November 7, 2008Publication date: May 28, 2009Applicant: Fujitsu LimitedInventors: Hirofumi AOTA, Kohei Shibata, Tamotsu Akashi, Tsuyoshi Yamamoto
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Publication number: 20090060416Abstract: A wavelength selective switch of the present invention angularly disperses lights output from a plurality of input ports of an input and output optical system, to an X-direction, according to wavelength, by a diffraction grating to supply the dispersed lights to a condenser lens. The condenser lens is arranged so that a center axis thereof is shifted to the X-direction relative to an axis passing through the center of spreading angle to the X-direction of output beams from the diffraction grating, and accordingly, at a non-operating time, the light of each wavelength passed through the condenser lens is incident on each movable mirror being tilted by an offset angle corresponding to a shift amount of the condenser lens. As a result, it becomes possible to block the connection between an input side and an output side at the non-operating time without degrading the performance at an operating time.Type: ApplicationFiled: March 11, 2008Publication date: March 5, 2009Applicant: Fujitsu LitmitedInventors: Tsuyoshi Yamamoto, Tamotsu Akashi, Kohei Shibata, Hirofumi Aota, Shinji Yamashita
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Patent number: 7476038Abstract: An optical device module includes an optical device, a soaking unit fixed to one surface of the optical device, a heating/cooling unit fixed to one surface of the soaking unit, a heat-insulating unit fixed to one surface of the heating/cooling unit, and a package that houses the optical device, the soaking unit, the heating/cooling unit, and the heat-insulating unit and to which the heat-insulating unit is fixed. The heating/cooling unit heats the optical device using self-generated heat or cools the optical device via the soaking unit.Type: GrantFiled: March 22, 2004Date of Patent: January 13, 2009Assignee: Fujitsu LimitedInventors: Yoichi Oikawa, Hirofumi Aota, Kazuaki Akimoto, Hideyuki Miyata, Yumi Nakazawa, legal representative, Tadao Nakazawa
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Publication number: 20080317405Abstract: An optical switch switches ports through which a beam is input and output and includes an optical system through which the beam passes; a movable reflector that is enclosed in a casing and reflects, at a variable angle, the beam that has passed through the optical system; and a transmissive window that is disposed in the casing at a position through which the beam passes, is made of a uniaxial crystal, and obtains a phase difference with respect to the beam passing therethrough having a wavelength ?. The phase difference is ?/4 times a positive odd integer and results from a setting of an orientation of a crystal axis and a thickness of the transmissive window.Type: ApplicationFiled: May 23, 2008Publication date: December 25, 2008Applicant: FUJITSU LIMITEDInventors: Hirofumi Aota, Kohei Shibata, Tamotsu Akashi, Tsuyoshi Yamamoto, Naoki Hashimoto
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Patent number: 7447399Abstract: In an optical switch comprising a wavelength spatially dispersive optical element for spatially dispersing a wavelength-multiplexed beam according to wavelengths, a plurality of output ports and a plurality of mirrors onto which beams dispersed by the element are irradiated, and each of which is able to direct a reflected beam to any one of the plural output ports, when an incident position of a reflected beam irradiated onto any one of the output ports is changed, the angle of the reflecting surface of a corresponding mirror among the plural mirrors is changed in a direction other than a direction in which the mirrors are arranged, whereby a protuberance in the vicinity of the out-band (side lobe) of the transmission band characteristic of the optical switch can be suppressed.Type: GrantFiled: March 18, 2005Date of Patent: November 4, 2008Assignee: Fujitsu LimitedInventors: Hirofumi Aota, Tamotsu Akashi
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Publication number: 20080240650Abstract: An optical switch includes an input port into which a multiplexed optical signal is input; a dispersing unit that, according to wavelength, disperses the multiplexed optical signal into a plurality of optical signals that are each dispersed in a unique direction; a converging unit that converges the dispersed optical signals; plural mirrors that are arrayed forming a single row in a plane and reflecting the converged optical signals, respectively; and plural output ports through which the reflected optical signals are output. Each of the mirrors has a concave reflective surface that is in the plane and of a predetermined curvature about an axis parallel to the plane.Type: ApplicationFiled: February 29, 2008Publication date: October 2, 2008Applicant: FUJITSU LIMITEDInventors: Kohei Shibata, Hirofumi Aota, Tamotsu Akashi, Toshiya Kishida, Hiroyuki Furukawa
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Publication number: 20080239441Abstract: The present mirror device for suppressing PDL on the assumption of multiple modes of angles of input light and output light to movable mirrors with respect to the crystal axis of a crystal member at the time light passes through the crystal member. The mirror device includes a mirror system 2 and a flat-shaped crystal member 3 which is arranged in such a manner that a first angle is not larger than a second angle. The crystal member is constructed in such a manner that a third angle is substantially equal to a half of a fourth angle.Type: ApplicationFiled: February 20, 2008Publication date: October 2, 2008Applicant: Fujitsu LimitedInventors: Hirofumi AOTA, Kohei Shibata, Tamotsu Akashi, Tsuyoshi Yamamoto