Patents by Inventor Yoichi Oikawa
Yoichi Oikawa 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).
-
Publication number: 20080166128Abstract: An optical apparatus comprising, converting units converting electrical signals into signal lights with different wavelength, polarization control units controlling polarizing states of the signal lights into polarization controlled lights respectively, an optical multiplexer multiplexing the polarization controlled lights into a multiplexed light, an optical branching unit branching the multiplexed light and outputting a branched light, a polarizing unit extracting only signal lights of the specified polarizing state from the branched light into an extracted light, and a control unit detecting intensity of the extracted light. Pilot signals are applied to modulate the electrical signals or the polarization controls. The polarization control units controls the polarizing states of the signal lights based on the pilot signal frequencies of the detection result by the control unit.Type: ApplicationFiled: December 4, 2007Publication date: July 10, 2008Applicant: Fujitsu LimitedInventors: Takashi TOYOMAKI, Noriaki Mizuguchi, Yoichi Oikawa
-
Patent number: 7379636Abstract: An optical switch having a plurality of switch cells. The optical switch has n inputs (n is a natural number) and m outputs (m is a natural number). The optical switch has a unit size defined as the distance between any two adjacent ones of the switch cells. The optical switch comprises a substrate having a switch size of K×L (K is an integer satisfying n?K, and L is an integer satisfying m?L), first and second mirrors parallel to each other and perpendicular to a principal surface of the substrate, and an optical unit providing a plurality of input optical paths for the n inputs and a plurality of output optical paths for the m outputs. The plurality of input optical paths are inclined relative to the first and second mirrors, and the plurality of output optical paths are inclined relative to the first and second mirrors. Each switch cell comprises a switch mirror provided movably relative to the substrate. With this configuration, the path dependence of loss is substantially eliminated.Type: GrantFiled: December 18, 2006Date of Patent: May 27, 2008Assignee: Fujitsu LimitedInventors: Yoichi Oikawa, Satoshi Kuroyanagi
-
Publication number: 20070297718Abstract: The distance between an optical diffraction device and a focusing lens, and the coefficient of the focal length change of the focusing lens, are adjusted based on the calculation expression of wavelength identification errors in light of temperature change of a member making up light receiving means (e.g., PD array), thereby performing correction of wavelength identification errors, whereby optical wavelength identification can be performed with high precision even when the temperature changes.Type: ApplicationFiled: April 9, 2007Publication date: December 27, 2007Applicant: FUJITSU LIMITEDInventor: Yoichi Oikawa
-
Patent number: 7269314Abstract: The present invention is a dispersion compensation device capable of varying dispersion compensation amount with a simple configuration. The device includes a first mode light conversion section capable of converting input light into light of higher mode, a dispersion compensation section capable of performing dispersion compensation on the higher mode light outputted from the first mode light conversion section corresponding to the status of mode of the higher mode light, a second mode light conversion section capable of converting the light of higher mode dispersion-compensated in the dispersion compensation section into light of original mode, and a mode control section capable of variably controlling the status of mode of the higher mode light converted in the first mode light conversion section, and controlling to convert the higher mode light from the dispersion compensation section to the light of original mode in the second mode light conversion section.Type: GrantFiled: February 3, 2005Date of Patent: September 11, 2007Assignee: Fujitsu LimitedInventor: Yoichi Oikawa
-
Publication number: 20070098321Abstract: An optical switch having a plurality of switch cells. The optical switch has n inputs (n is a natural number) and m outputs (m is a natural number). The optical switch has a unit size defined as the distance between any two adjacent ones of the switch cells. The optical switch comprises a substrate having a switch size of K×L (K is an integer satisfying n?K, and L is an integer satisfying m?L), first and second mirrors parallel to each other and perpendicular to a principal surface of the substrate, and an optical unit providing a plurality of input optical paths for the n inputs and a plurality of output optical paths for the m outputs. The plurality of input optical paths are inclined relative to the first and second mirrors, and the plurality of output optical paths are inclined relative to the first and second mirrors. Each switch cell comprises a switch mirror provided movably relative to the substrate. With this configuration, the path dependence of loss is substantially eliminated.Type: ApplicationFiled: December 18, 2006Publication date: May 3, 2007Applicant: Fujitsu LimitedInventors: Yoichi Oikawa, Satoshi Kuroyanagi
-
Patent number: 7206476Abstract: An optical switch having a plurality of switch cells. The optical switch has n inputs (n is a natural number) and m outputs (m is a natural number). The optical switch has a unit size defined as the distance between any two adjacent ones of the switch cells. The optical switch comprises a substrate having a switch size of K×L (K is an integer satisfying n?K, and L is an integer satisfying m?L), first and second mirrors parallel to each other and perpendicular to a principal surface of the substrate, and an optical unit providing a plurality of input optical paths for the n inputs and a plurality of output optical paths for the m outputs. The plurality of input optical paths are inclined relative to the first and second mirrors, and the plurality of output optical paths are inclined relative to the first and second mirrors. Each switch cell comprises a switch mirror provided movably relative to the substrate. With this configuration, the path dependence of loss is substantially eliminated.Type: GrantFiled: May 6, 2005Date of Patent: April 17, 2007Assignee: Fujitsu LimitedInventors: Yoichi Oikawa, Satoshi Kuroyanagi
-
Patent number: 7151866Abstract: An optical device module includes an optical device with a plurality of electrodes disposed at predetermined positions, a substrate disposed oppositely to the optical device and with wiring patterns for connecting to the electrodes, and a wiring which connects the electrodes to the wiring patterns.Type: GrantFiled: March 24, 2004Date of Patent: December 19, 2006Assignee: Fujitsu LimitedInventors: Yoichi Oikawa, Hirofumi Aota, Kazuaki Akimoto, Hideyuki Miyata, Yumi Nakazawa, legal representative, Tadao Nakazawa, deceased
-
Patent number: 7106927Abstract: Optical cross-connect apparatus including first wavelength converters converting m different wavelengths ?1 through ?m contained in n WDM input optical signals into 2m wavelengths ?1 through ?2m; a first wavelength cross-connector performing cross-connection according to wavelengths, separating the optical signals wavelength-converted by the first wavelength converters into 2m wavelengths combining optical signals with the 2m separated wavelengths; second wavelength converters converting the 2m wavelengths contained in the optical signals cross-connected by the first wavelength cross-connector into 2m wavelengths; a second wavelength cross-connector performing cross-connection according to wavelengths separating the optical signals wavelength-converted by the second wavelength converters into 2m wavelengths and combining optical signals with the 2m separated wavelengths; and third wavelength converters converting the 2m wavelengths ?1 through ?2m in the optical signals cross-connected by the second wavelengthType: GrantFiled: February 20, 2004Date of Patent: September 12, 2006Assignee: Fujitsu LimitedInventor: Yoichi Oikawa
-
Publication number: 20060198583Abstract: A wavelength selective switch of the invention, separates WDM light coming out from an input fiber of a fiber collimator array according to its wavelength, in a diffraction grating, and reflects each wavelength channel proceeding in different directions by MEMS mirrors corresponding to a mirror array. In the MEMS mirrors, the angles of their reflecting surfaces are set corresponding to the location of the output port which is set in the output address of the wavelength channel to be injected. For each of the wavelength channels that reach the target output port, one part of each is reflected by the end face of an output fiber, and the reflected light is returned to the input port, and sent to a channel monitor via an optical circulator, so that the optical power corresponding to each wavelength channel is monitored.Type: ApplicationFiled: June 22, 2005Publication date: September 7, 2006Applicant: FUJITSU LIMITEDInventors: Yoichi Oikawa, Kazuaki Akimoto
-
Publication number: 20060127001Abstract: The present invention is a dispersion compensation device capable of varying dispersion compensation amount with a simple configuration. The device includes a first mode light conversion section capable of converting input light into light of higher mode, a dispersion compensation section capable of performing dispersion compensation on the higher mode light outputted from the first mode light conversion section corresponding to the status of mode of the higher mode light, a second mode light conversion section capable of converting the light of higher mode dispersion-compensated in the dispersion compensation section into light of original mode, and a mode control section capable of variably controlling the status of mode of the higher mode light converted in the first mode light conversion section, and controlling to convert the higher mode light from the dispersion compensation section to the light of original mode in the second mode light conversion section.Type: ApplicationFiled: February 3, 2005Publication date: June 15, 2006Applicant: Fujitsu LimitedInventor: Yoichi Oikawa
-
Patent number: 6999648Abstract: An optical cross-connect apparatus that realizes high throughput in optical cross-connection by performing large-scale switching. An input optical signal processing section converts wavelengths contained in each input WDM signal into wavelengths the number of which is equal to the number of WDM signals, compresses the pulse widths of the WDM signals by dividing the pulse widths by the number of the wavelengths contained in each input WDM signal, and performs a phase shift so that the phases of a plurality of compressed signal will not be the same. A wavelength switching section includes passive optical devices and distributes the optical signals processed by the input optical signal processing section according to wavelengths. An output optical signal processing section converts wavelengths contained in the optical signals distributed by the wavelength switching section into wavelengths recognized from the phases of the optical signals, expands the pulse widths of the optical signals, and outputs WDM signals.Type: GrantFiled: February 26, 2004Date of Patent: February 14, 2006Assignee: Fujitsu LimitedInventors: Yoichi Oikawa, Makoto Murakami, Takehisa Ishikawa
-
Publication number: 20050220397Abstract: In a CWDM optical transmission system of the present invention, in place of an optical signal of at least one wave among a plurality of optical signals corresponding to a CWDM system, a DWDM light output from an additional light transmission unit of a DWDM system is given to a multiplexer via a variable optical attenuator, and multiplexed with the optical signals corresponding to CWDM, to be sent out to a transmission path. At this time, the total power of the DWDM light sent out to the transmission path, is attenuated by the variable optical attenuator, so as to be approximately equal to the power per one wavelength of the CWDM light. On an optical reception terminal, the light propagated through the transmission path is demultiplexed by a demultiplexer, and the DWDM light corresponding to the additional wavelengths is amplified by an optical amplifier and thereafter, received by an additional light reception unit.Type: ApplicationFiled: January 25, 2005Publication date: October 6, 2005Applicant: Fujitsu LimitedInventors: Yoichi Oikawa, Takashi Toyomaki, Tomoyuki Ohtsuka
-
Publication number: 20050196098Abstract: An optical switch having a plurality of switch cells. The optical switch has n inputs (n is a natural number) and m outputs (m is a natural number). The optical switch has a unit size defined as the distance between any two adjacent ones of the switch cells. The optical switch comprises a substrate having a switch size of K×L (K is an integer satisfying n?K, and L is an integer satisfying m?L), first and second mirrors parallel to each other and perpendicular to a principal surface of the substrate, and an optical unit providing a plurality of input optical paths for the n inputs and a plurality of output optical paths for the m outputs. The plurality of input optical paths are inclined relative to the first and second mirrors, and the plurality of output optical paths are inclined relative to the first and second mirrors. Each switch cell comprises a switch mirror provided movably relative to the substrate. With this configuration, the path dependence of loss is substantially eliminated.Type: ApplicationFiled: May 6, 2005Publication date: September 8, 2005Applicant: Fujitsu LimitedInventors: Yoichi Oikawa, Satoshi Kuroyanagi
-
Patent number: 6907154Abstract: An optical switch having a plurality of switch cells. The optical switch has n inputs (n is a natural number) and m outputs (m is a natural number). The optical switch has a unit size defined as the distance between any two adjacent ones of the switch cells. The optical switch comprises a substrate having a switch size of K×L (K is an integer satisfying n?K, and L is an integer satisfying m?L), first and second mirrors parallel to each other and perpendicular to a principal surface of the substrate, and an optical unit providing a plurality of input optical paths for the n inputs and a plurality of output optical paths for the m outputs. The plurality of input optical paths are inclined relative to the first and second mirrors, and the plurality of output optical paths are inclined relative to the first and second mirrors. Each switch cell comprises a switch mirror provided movably relative to the substrate. With this configuration, the path dependence of loss is substantially eliminated.Type: GrantFiled: August 9, 2001Date of Patent: June 14, 2005Assignee: Fujitsu LimitedInventors: Yoichi Oikawa, Satoshi Kuroyanagi
-
Patent number: 6901179Abstract: Disclosed herein is an optical switch including a plurality of switch cells arranged in the form of an n×n matrix (n is an integer), each switch cell having first and second input ends and first and second output ends, and 2(n?1) reflection cells. The plural switch cells are selectively driven so that one of the first and second input ends of the switch cells in the first column is optically connected to one of the first and second output ends of the switch cells in the n-th column. (n?1) ones of the 2(n?1) reflection cells are arranged so as to optically connect the first output end of the switch cell in the first row, the i-th column (i is an integer satisfying 1?i?(n?1)) to the first input end of the switch cell in the first row, the (i+1)-th column.Type: GrantFiled: April 6, 2004Date of Patent: May 31, 2005Assignee: Fujitsu LimitedInventor: Yoichi Oikawa
-
Publication number: 20050105908Abstract: An optical repeater which includes a wavelength converter and a bit rate converter. The wavelength converter converts a wavelength of an optical signal from a first optical network to a wavelength of a second optical network. The bit rate converter converts a bit rate of the optical signal from the first optical network to a bit rate of the second optical network. The optical repeater transmits the optical signal from the first optical network to the second optical network at the converted bit rate and wavelength.Type: ApplicationFiled: September 16, 2004Publication date: May 19, 2005Applicant: Fujitsu LimitedInventor: Yoichi Oikawa
-
Publication number: 20050094143Abstract: The invention aims to provide a miniaturized polarization measuring apparatus which can measure the polarization of input signal light with high accuracy, even in an optical system where a plurality of light receiving elements are arranged adjacent to each other.Type: ApplicationFiled: May 12, 2004Publication date: May 5, 2005Applicant: Fujitsu LimitedInventors: Teruhiro Kubo, Yoichi Oikawa
-
Publication number: 20050089275Abstract: An optical device module includes an optical device with a plurality of electrodes disposed at predetermined positions, a substrate disposed oppositely to the optical device and with wiring patterns for connecting to the electrodes, and a wiring which connects the electrodes to the wiring patterns.Type: ApplicationFiled: March 24, 2004Publication date: April 28, 2005Applicant: FUJITSU LIMITEDInventors: Yoichi Oikawa, Hirofumi Aota, Kazuaki Akimoto, Hideyuki Miyata, Yumi Nakazawa, Tadao Nakazawa
-
Publication number: 20050089282Abstract: 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: ApplicationFiled: March 22, 2004Publication date: April 28, 2005Applicant: FUJITSU LIMITEDInventors: Yoichi Oikawa, Hirofumi Aota, Kazuaki Akimoto, Hideyuki Miyata, Tadao Nakazawa, Yumi Nakazawa
-
Patent number: 6819828Abstract: Disclosed herein is a method including the steps of wavelength division multiplexing a plurality of optical signals having different wavelengths to obtain resultant WDM signal light; transmitting the WDM signal light by an optical fiber transmission line; supplying reference light having a predetermined wavelength to the optical fiber transmission line; generating four-wave mixing in the optical fiber transmission line by the interaction of the WDM signal light and the reference light; detecting the power of light generated as the result of the four-wave mixing; and controlling the power of the WDM signal light to be supplied to the optical fiber transmission line according to the power detected. According to this method, the effect of four-wave mixing can be suppressed.Type: GrantFiled: September 26, 2001Date of Patent: November 16, 2004Assignee: Fujitsu LimitedInventors: Tsukasa Takahashi, Toshihiro Ohtani, Yoichi Oikawa