Patents by Inventor Masataka Shirasaki
Masataka Shirasaki 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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Patent number: 6717731Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: GrantFiled: October 1, 2002Date of Patent: April 6, 2004Assignees: Fujitsu Limited, Avanex CorporationInventors: Masataka Shirasaki, Simon Cao
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Publication number: 20030214737Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: ApplicationFiled: June 12, 2003Publication date: November 20, 2003Applicant: Fujitsu LimitedInventors: Masataka Shirasaki, Simon Cao
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Publication number: 20030179989Abstract: An optical wavelength division multiplexed system uses wavelength splitters to split channels included in input light into different paths within the system. Odd-numbered channels are split into one path, and even-numbered channels are split into another path, providing increased isolation between channels. Using filters, the system then drops one or more of the isolated, split channels into paths referred to as dropped paths and allows the remaining channels to continue through the filters into output paths. The dropped paths are then combined into one, common dropped path, and the output paths are also combined into one, common output path.Type: ApplicationFiled: March 19, 2003Publication date: September 25, 2003Applicant: FUJITSU LIMITEDInventor: Masataka Shirasaki
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Patent number: 6607278Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: GrantFiled: September 10, 2002Date of Patent: August 19, 2003Assignees: Fujitsu Limited, Avanex CorporationInventors: Masataka Shirasaki, Simon Cao
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Publication number: 20030081318Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: ApplicationFiled: October 1, 2002Publication date: May 1, 2003Applicant: FUJITSU LIMITEDInventors: Masataka Shirasaki, Simon Cao
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Patent number: 6556742Abstract: An optical wavelength division multiplexed system uses wavelength splitters to split channels included in input light into different paths within the system. Odd-numbered channels are split into one path, and even-numbered channels are split into another path, providing increased isolation between channels. Using filters, the system then drops one or more of the isolated, split channels into paths referred to as dropped paths and allows the remaining channels to continue through the filters into output paths. The dropped paths are then combined into one, common dropped path, and the output paths are also combined into one, common output path.Type: GrantFiled: November 4, 1998Date of Patent: April 29, 2003Assignee: Fujitsu LimitedInventor: Masataka Shirasaki
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Publication number: 20030053783Abstract: The invention relates to apparatus and methods for reducing the temperature sensitivity of optical fibers. According to one embodiment, the temperature insensitive optical fiber includes a core having a temperature dependent optical length and a cladding surrounding the core. The temperature insensitive fiber further includes an expansion control coating substantially surrounding the cladding. The expansion control coating has a coefficient of thermal expansion and is adapted to modify the temperature dependence of the optical length. The temperature insensitive optical fiber can be used in a fiber interferometer to substantially compensate the interferometer output signal over an operating temperature range. The temperature insensitive optical fiber can also be adapted for fiber diffraction gratings.Type: ApplicationFiled: September 18, 2001Publication date: March 20, 2003Inventor: Masataka Shirasaki
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Publication number: 20030021046Abstract: Various configurations of a virtually imaged phased array (VIPA) generator in combination with a mirror to compensate for chromatic dispersion. A VIPA generator produces a light traveling from the VIPA generator. In some embodiments, a variable curvature mirror is positioned to reflect the light back to the VIPA generator. A rotation axis around which the mirror is rotated and a translation path for the rotation axis are provided, to change the curvature of the mirror where the output light is reflected. In other embodiments, a plurality of mirrors have different surface curvatures. A holder has a rotation axis and holds the plurality of mirrors equidistantly from the rotation axis. The holder is rotatable around the rotation axis to bring a different, respective mirror in position to reflect light produced by a VIPA generator back to the VIPA generator. In other embodiments, a rotating mirror is rotatable about a rotation axis to reflect light produced by a VIPA generator to a respective fixed mirror.Type: ApplicationFiled: September 24, 2002Publication date: January 30, 2003Applicant: FUJITSU LIMITEDInventors: Simon Xiaofan Cao, Masataka Shirasaki
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Publication number: 20030012250Abstract: The invention relates to apparatus and methods for tuning the wavelength of a laser. According to one embodiment, the wavelength tunable filter includes a first wavelength selective element having a first thickness, a first refractive index and a first spectral response having a plurality of transmission peaks having an associated first period. The filter also includes a second wavelength selective element having a second thickness, a second refractive index and a second spectral response having a plurality of transmission peaks having an associated second period. Additionally, the filter includes a control module to vary at least one of the first thickness, the second thickness, the first refractive index, and the second refractive index such that one of the plurality of transmission peaks of the first spectral response substantially overlaps one of the plurality of transmission peaks of the second spectral response.Type: ApplicationFiled: June 25, 2001Publication date: January 16, 2003Inventor: Masataka Shirasaki
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Publication number: 20030007264Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: ApplicationFiled: September 10, 2002Publication date: January 9, 2003Applicant: FUJITSU LIMITEDInventors: Masataka Shirasaki, Simon Cao
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Publication number: 20030002784Abstract: The invention relates to an optical bandpass filter and a method for filtering an optical signal having a plurality of WDM component wavelengths. The optical bandpass filter includes a spectrally dispersive element and an optical module. The spectrally dispersive element is adapted to receive the optical signal and to provide a dispersed optical signal to the optical module. The optical module returns predetermined WDM component wavelengths to the spectrally dispersive element. The predetermined WDM component wavelengths are imaged to predetermined locations.Type: ApplicationFiled: June 25, 2001Publication date: January 2, 2003Inventor: Masataka Shirasaki
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Publication number: 20020196816Abstract: In one embodiment, the invention relates to a tunable laser system. The laser system includes a first optical path at a first wavelength having a first path length and a second optical path at a second wavelength having a second path length. The first and second optical paths partially overlap in a shared path region that is shorter than either the first or second path lengths. The first and second path lengths are substantially equal. The laser system also includes an optical modulator that is located within the shared path. The laser system selects a wavelength of an optical pulse according to a sequence of drive signals from the drive signal generator. In another embodiment the laser system additionally includes a Fabry-Perot filter located in one of the shared paths. In operation of this embodiment, the laser system generates a series of optical pulses of different wavelengths.Type: ApplicationFiled: November 30, 2001Publication date: December 26, 2002Inventor: Masataka Shirasaki
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Patent number: 6481861Abstract: Various configurations of a virtually imaged phased array (VIPA) generator in combination with a mirror to compensate for chromatic dispersion. A VIPA generator produces a light traveling from the VIPA generator. In some embodiments, a variable curvature mirror is positioned to reflect the light back to the VIPA generator. A rotation axis around which the mirror is rotated and a translation path for the rotation axis are provided, to change the curvature of the mirror where the output light is reflected. In other embodiments, a plurality of mirrors have different surface curvatures. A holder has a rotation axis and holds the plurality of mirrors equidistantly from the rotation axis. The holder is rotatable around the rotation axis to bring a different, respective mirror in position to reflect light produced by a VIPA generator back to the VIPA generator. In other embodiments, a rotating mirror is rotatable about a rotation axis to reflect light produced by a VIPA generator to a respective fixed mirror.Type: GrantFiled: December 19, 2001Date of Patent: November 19, 2002Assignees: Fujitsu Limited, Avanex CorporationInventors: Simon Xiaofan Cao, Masataka Shirasaki
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Patent number: 6478433Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: GrantFiled: October 30, 2001Date of Patent: November 12, 2002Assignees: Fujitsu Limited, Avanex CorporationInventors: Masataka Shirasaki, Simon Cao
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Patent number: 6471361Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the: apparatus provides chromatic dispersion to the input light. The modified cone shape of the mirror can be designed so that the apparatus provides a uniform chromatic dispersion to light in the.Type: GrantFiled: February 27, 2002Date of Patent: October 29, 2002Assignees: Fujitsu Limited, Avanex CorporationInventors: Masataka Shirasaki, Simon Cao
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Publication number: 20020114090Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: ApplicationFiled: February 27, 2002Publication date: August 22, 2002Applicant: FUJITSU LIMITEDInventors: Masataka Shirasaki, Simon Cao
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Publication number: 20020093748Abstract: Various configurations of a virtually imaged phased array (VIPA) generator in combination with a mirror to compensate for chromatic dispersion. A VIPA generator produces a light traveling from the VIPA generator. In some embodiments, a variable curvature mirror is positioned to reflect the light back to the VIPA generator. A rotation axis around which the mirror is rotated and a translation path for the rotation axis are provided, to change the curvature of the mirror where the output light is reflected. In other embodiments, a plurality of mirrors have different surface curvatures. A holder has a rotation axis and holds the plurality of mirrors equidistantly from the rotation axis. The holder is rotatable around the rotation axis to bring a different, respective mirror in position to reflect light produced by a VIPA generator back to the VIPA generator. In other embodiments, a rotating mirror is rotatable about a rotation axis to reflect light produced by a VIPA generator to a respective fixed mirror.Type: ApplicationFiled: December 19, 2001Publication date: July 18, 2002Applicant: FUJITSU LIMITEDInventors: Simon Xiaofan Cao, Masataka Shirasaki
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Patent number: 6390633Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: GrantFiled: June 8, 2001Date of Patent: May 21, 2002Assignees: Fujitsu Limited, Avanex CorporationInventors: Masataka Shirasaki, Simon Cao
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Publication number: 20020044364Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.Type: ApplicationFiled: October 30, 2001Publication date: April 18, 2002Applicant: FUJITSU LIMITEDInventors: Masataka Shirasaki, Simon Cao
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Publication number: 20020025109Abstract: An optical wavelength division multiplexed system uses wavelength splitters to split channels included in input light into different paths within the system. Odd-numbered channels are split into one path, and even-numbered channels are split into another path, providing increased isolation between channels. Using filters, the system then drops one or more of the isolated, split channels into paths referred to as dropped paths and allows the remaining channels to continue through the filters into output paths. The dropped paths are then combined into one, common dropped path, and the output paths are also combined into one, common output path.Type: ApplicationFiled: November 4, 1998Publication date: February 28, 2002Inventor: MASATAKA SHIRASAKI