Patents Assigned to Photonics Electronics Technology Research Association
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Publication number: 20200150340Abstract: An optical transmitter-receiver includes an optical integrated device in which at least an optical modulator and an optical detector are integrated as optical devices over the same substrate and an insulating layer is provided between the optical modulator and the substrate and between the optical detector and the substrate, and an electronic circuit chip that is connected to the optical integrated device and includes an electronic circuit including a ground wiring line. The optical integrated device includes a shield electrode between the optical modulator and the optical detector, and the shield electrode is provided sandwiching the insulating layer with the substrate to configure a capacitance and is connected to the ground wiring line of the electronic circuit chip.Type: ApplicationFiled: October 31, 2019Publication date: May 14, 2020Applicants: FUJITSU LIMITED, Photonics Electronics Technology Research AssociationInventors: Shinsuke Tanaka, Tatsuya Usuki
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Patent number: 10644822Abstract: A network system comprises a plurality of nodes and a plurality of optical amplifiers. A first node comprises a first transmitter configured to send a wavelength-division-multiplexed optical signal and a first receiver configured to receive a wavelength-division-multiplexed optical signal, and the second node comprises a second transmitter configured to send a wavelength-division-multiplexed optical signal and a second receiver configured to receive a wavelength-division-multiplexed optical signal. The first and second transmitters are optically connected to an input of the first optical amplifier and an input of the second optical amplifier, respectively, and the first and second receivers are optically connected to an output of the first optical amplifier and an output of the second optical amplifier, respectively. The receivers each comprise a photoreceiver and a reception circuit. The photoreceiver is electrically connected, by flip chip connection, to a reception circuit.Type: GrantFiled: September 6, 2017Date of Patent: May 5, 2020Assignee: PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Yutaka Urino
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Publication number: 20200132951Abstract: An optical device includes a light-emitting element; an electronic circuit chip; a substrate on which the light-emitting element and the electronic circuit chip are mounted; a first electrode formed on a first mounting surface of the light-emitting element on the substrate; and a second electrode formed on a second mounting surface of the electronic circuit chip on the substrate. The first electrode and the second electrode have the same structure.Type: ApplicationFiled: October 21, 2019Publication date: April 30, 2020Applicants: FUJITSU LIMITED, NEC Corporation, Photonics Electronics Technology Research AssociationInventors: Nobuaki HATORI, Keizo KINOSHITA
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Publication number: 20200136729Abstract: An optical transmission apparatus includes first and second optical waveguides to transmit light of multiple wavelengths; optical couplers on the waveguides, to couple the lights transmitted through the waveguides, so as to output the coupled light to the waveguides; phase shifters provided at preceding stages of part of the optical couplers, to change a phase shift amount of the light transmitted through the first and/or second optical waveguides, wherein the number of optical couplers in the part is greater than or equal to the number of the types of wavelengths; a monitor to monitor the intensity of the light output to the second optical waveguide via the optical coupler at the last stage; and a controller to control the phase shifters by changing the phase shift amount for each of the phase shifters in a direction in which the output of the monitor decreases.Type: ApplicationFiled: October 17, 2019Publication date: April 30, 2020Applicants: FUJITSU LIMITED, Photonics Electronics Technology Research AssociationInventor: Tomoyuki AKIYAMA
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Publication number: 20200092196Abstract: A parallel computer system includes: direct links that forms a direct connection between a sending node and a receiving node, one-hop links that forms a connection between a sending node and a receiving node by way of a return node that is other than the sending node and the receiving node, and a communication control unit that, when transferring data from a sending node to a receiving node, selects the link that connects the sending node and the receiving node from among a link that uses only a direct link, a link that uses only a one-hop link, and a link that forms a connection combines and uses the direct link and the one-hop link.Type: ApplicationFiled: September 6, 2019Publication date: March 19, 2020Applicants: NEC CORPORATION, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATION, FUJITSU LIMITEDInventors: Kenji MIZUTANI, Yutaka URINO, Tatsuya USUKI
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Patent number: 10580923Abstract: A disclosed optical semiconductor device includes a first semiconductor layer having a first refractive index and a first optical absorption coefficient; and a second semiconductor layer formed on the first semiconductor layer, the second semiconductor layer having a second refractive index and a second optical absorption coefficient. The second refractive index is larger than the first refractive index, and the second optical absorption coefficient is larger than the first optical absorption coefficient. The first semiconductor layer includes a first region of p-type, a second region of n-type, a third region of p-type or n-type between the first region and the second region, a fourth region of i-type between the first region and the third region, and a fifth region of i-type between the second region and the third region. The second semiconductor layer is formed on the first region, the fourth region, and the third region.Type: GrantFiled: May 30, 2019Date of Patent: March 3, 2020Assignees: FUJITSU LIMITED, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Takasi Simoyama
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Patent number: 10547406Abstract: An optical element includes a gain chip, a ring modulator, which is a band-pass filter, a first optical waveguide and a second optical waveguide that are optically connected to the ring modulator, and a heater, wherein the first optical waveguide and the second optical waveguide are formed to be equal in optical path length (have no difference in optical path length) between a first light coupling point and a second light coupling point and equal in shape and length between the first light coupling point and the second light coupling point (to be symmetrical with the ring modulator interposed therebetween (with respect to the ring modulator)).Type: GrantFiled: July 6, 2017Date of Patent: January 28, 2020Assignees: FUJITSU LIMITED, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Tomoyuki Akiyama
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Patent number: 10535786Abstract: Provided is a light receiving element with high light receiving sensitivity. The light receiving element comprises: a light absorbing layer that absorbs light to generate a carrier; and a diffraction element that converts the optical path of first polarized light, which is obliquely incident on a plane formed by the light absorbing layer, so that the first polarized light propagates in a first direction along the light absorbing layer, and that converts the optical path of second polarized light incident from the same direction as the first polarized light so that the second polarized light propagates in a second direction, opposite the first direction, along the light absorbing layer.Type: GrantFiled: December 16, 2015Date of Patent: January 14, 2020Assignee: PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventors: Kenichiro Yashiki, Jun Ushida, Masatoshi Tokushima, Kazuhiko Kurata
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Publication number: 20190384135Abstract: Provided is a SIS-type electro-optic modulator capable of realizing highly efficient optical coupling with a rib-type Si waveguide, improving modulation efficiency, realizing reduction of electric capacity and lead-out resistance in stacked semiconductor layers. The modulator includes a SIS junction constituted by first and second semiconductor layers having different type of conductivity and a dielectric layer interposed therebetween, wherein an electrical signal from electrodes coupled to the first and second semiconductor layers causes free carriers accumulate, deplete or invert on both sides of the dielectric layer, thereby modulating a free carrier concentration felt by an optical signal electric filed, light having a polarization component orthogonal to the width direction of the SIS junction is incident on the dielectric layer, and the width of the SIS junction is ?/neff or less (? is the wavelength of the incident light and neff is an effective refractive index of the modulator to the incident light).Type: ApplicationFiled: June 13, 2019Publication date: December 19, 2019Applicants: NEC CORPORATION, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventors: Shigeki TAKAHASHI, Junichi FUJIKATA
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Optical transport apparatus, optical demultiplexer, and method of controlling optical demultiplexing
Patent number: 10491321Abstract: An optical demultiplexer has at least one unit circuit formed by three AMZs having a same arm length difference and cascaded in a tree structure in which two output ports of the 1st AMZ are connected to the 2nd AMZ and the 3rd AMZ, respectively, wherein the unit circuit has first and second monitors connected to the first and second output ports of the 2nd AMZ, and third and fourth monitors connected to the first and second output ports of the 3rd AMZ, a first control circuit controlling the transmissivity of the 1st AMZ so as to increase the monitoring result of the second and fourth monitors, a second control circuit controlling the transmissivity of the 2nd AMZ to decrease the monitoring result of the first monitor, and a third control circuit controlling the transmissivity of the 3rd AMZ to decrease the monitoring result of the third monitor.Type: GrantFiled: January 23, 2019Date of Patent: November 26, 2019Assignees: FUJITSU LIMITED, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Tomoyuki Akiyama -
Patent number: 10488596Abstract: The invention relates to an optical fiber mounted photonic integrated circuit device, wherein the tolerance for positioning in terms of the coupling between the single mode optical fibers and the optical waveguides provided on the photonic integrated circuit device is increased. An optical waveguide core group is provided in such a manner where a plurality of optical waveguide cores having a portion that is tapered in the direction of the width within a plane are aligned parallel to each other at intervals that allow for mutual directional coupling and that are narrower than the width of the core of the single mode optical fiber, and the inclined connection end surface of the single mode optical fiber and the upper surface of an end portion of the optical waveguide cores face each other for coupling.Type: GrantFiled: August 28, 2017Date of Patent: November 26, 2019Assignees: FUJITSU LIMITED, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Tomoyuki Akiyama
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Patent number: 10439729Abstract: A demultiplexing unit that is provided in an optical device and performs demultiplexing into a plurality of optical signals having wavelengths different from each other includes a plurality of optical filters that are coupled in multiple stages and in which a period of a peak wavelength of a transmission spectrum differs among different stages, a monitoring optical filter coupled to one of the plurality of optical filters, a monitoring photodetector coupled to the output side of the monitoring optical filter, and a plurality of wavelength adjustment units that are provided individually for the plurality of optical filters and the monitoring optical filter and cause wavelength shifts of an equal amount in a same direction.Type: GrantFiled: August 30, 2018Date of Patent: October 8, 2019Assignees: FUJITSU LIMITED, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Tomoyuki Akiyama
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Publication number: 20190285916Abstract: An electro-absorption optical modulator capable of realizing optical coupling with a Si waveguide with high efficiency, improving modulation efficiency, reducing light absorption by an electrode layer and achieving low optical loss includes a substrate; a first silicon layer doped to exhibit a first type of conductivity and a second silicon layer doped to exhibit a second type of conductivity that are disposed parallel to the substrate; and a Ge1?xSix (0<x<1)/Si stack in which a Ge1?xSix layer and a Si layer are stacked on the first and second silicon layers in this order.Type: ApplicationFiled: March 15, 2019Publication date: September 19, 2019Applicants: NEC CORPORATION, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Junichi FUJIKATA
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Publication number: 20190268085Abstract: In an embodiment, a network system comprises a plurality of nodes and a plurality of optical amplifiers. A first node comprises a first transmitter configured to send a wavelength-division-multiplexed optical signal and a first receiver configured to receive a wavelength-division-multiplexed optical signal, and the second node comprises a second transmitter configured to send a wavelength-division-multiplexed optical signal and a second receiver configured to receive a wavelength-division-multiplexed optical signal. The first transmitter and the second transmitter are optically connected to an input of the first optical amplifier and an input of the second optical amplifier, respectively, and the first receiver and the second receiver are optically connected to an output of the first optical amplifier and an output of the second optical amplifier, respectively. Each of the first photoreceiver and the second photoreceiver comprises a photoreceiver and a reception circuit.Type: ApplicationFiled: September 6, 2017Publication date: August 29, 2019Applicant: PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Yutaka Urino
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Patent number: 10389083Abstract: A modulated light source includes a reflective semiconductor optical amplifier including a mirror at a first end of the reflective semiconductor optical amplifier, a modulator configured to modulate a central wavelength, a first mirror configured to reflect light transmitted by the modulator, an optical filter disposed between a second end of the reflective semiconductor optical amplifier and the modulator, and a second mirror configured to reflect part of incoming light and to transmit the other part of the incoming light. The reflective semiconductor optical amplifier, the optical filter, and the second mirror configure a Fabry-Perot laser. The first mirror is configured to feed light emitted from the Fabry-Perot laser back to the Fabry-Perot laser, and the modulated light source is configured to select light corresponding to one of longitudinal modes oscillated by the Fabry-Perot laser, to modulate the selected light, and to output the modulated light.Type: GrantFiled: September 21, 2018Date of Patent: August 20, 2019Assignees: FUJITSU LIMITED, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventor: Tomoyuki Akiyama
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OPTICAL TRANSPORT APPARATUS, OPTICAL DEMULTIPLEXER, AND METHOD OF CONTROLLING OPTICAL DEMULTIPLEXING
Publication number: 20190245642Abstract: An optical demultiplexer has at least one unit circuit formed by three AMZs having a same arm length difference and cascaded in a tree structure in which two output ports of the 1st AMZ are connected to the 2nd AMZ and the 3rd AMZ, respectively, wherein the unit circuit has first and second monitors connected to the first and second output ports of the 2nd AMZ, and third and fourth monitors connected to the first and second output ports of the 3rd AMZ, a first control circuit controlling the transmissivity of the 1st AMZ so as to increase the monitoring result of the second and fourth monitors, a second control circuit controlling the transmissivity of the 2nd AMZ to decrease the monitoring result of the first monitor, and a third control circuit controlling the transmissivity of the 3rd AMZ to decrease the monitoring result of the third monitor.Type: ApplicationFiled: January 23, 2019Publication date: August 8, 2019Applicants: FUJITSU LIMITED, Photonics Electronics Technology Research AssociationInventor: Tomoyuki AKIYAMA -
Patent number: 10353225Abstract: The purpose of the present invention is to allow a silicon photonics modulator to be operated at high speed with high frequency by providing an electrode structure for the small multichannel high-density silicon photonics modulator. This electrode structure for a silicon photonics modulator includes, on the planar surface of a silicon substrate, a first layer for forming a plurality of bias electrical wirings, and a second layer formed by aligning each of a plurality of ground electrode portions and each electrical wiring in the first layer.Type: GrantFiled: August 11, 2015Date of Patent: July 16, 2019Assignee: PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventors: Kenichiro Yashiki, Yasuyuki Suzuki
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Patent number: 10340399Abstract: Provided is an optical device in which an Si cap layer is provided on a Ge layer, and which is capable of effectively reducing dark current, while having a good effect on prevention of production line contamination by Ge. One embodiment of the optical device according to the present invention is provided with: a semiconductor layer which contains Ge and has a (001) surface and a facet surface between the (001) surface and a (110) surface; and a cap layer which is formed from Si, and which is formed on the (001) surface and the facet surface of the semiconductor layer. The ratio of the film thickness of the cap layer on the facet surface to the film thickness of the cap layer on the (001) surface is 0.4 or more; and the film thickness of the cap layer on the (001) surface is from 9 nm to 30 nm (inclusive).Type: GrantFiled: July 28, 2016Date of Patent: July 2, 2019Assignee: PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventors: Shigekazu Okumura, Tohru Mogami, Keizo Kinoshita, Tsuyoshi Horikawa, Junichi Fujikata
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Publication number: 20190131761Abstract: A semiconductor light-emitting device includes an active layer including quantum dots, a diffraction grating, a low-reflectance film disposed at a light-emitting end of the active layer, and a high-reflectance film disposed at another end of the active layer and having an optical reflectance higher than an optical reflectance of the low-reflectance film.Type: ApplicationFiled: October 30, 2018Publication date: May 2, 2019Applicants: FUJITSU LIMITED, Photonics Electronics Technology Research AssociationInventor: Nobuaki Hatori
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Patent number: 10274757Abstract: An electro-optic device includes a first semiconductor layer including the rib-type waveguide, which includes a rib part and a first slab part, which extends in a first direction from the rib part; a dielectric layer, which is formed on the rib part; a second semiconductor layer, which extends in a second direction, which is opposite to the first direction, from an upper surface of the dielectric layer; a first high-concentration impurity region, which is formed in the first semiconductor layer to be in contact with the first slab part on the first direction side; and a second high-concentration impurity region, which is formed in a region of the second semiconductor layer on the second direction side. The second high-concentration impurity region is formed in a region other than a region overlapping the first semiconductor layer in a lamination direction.Type: GrantFiled: February 17, 2016Date of Patent: April 30, 2019Assignees: NEC CORPORATION, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATIONInventors: Junichi Fujikata, Shigeki Takahashi