Patents by Inventor Suguru Imai
Suguru Imai 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).
-
Patent number: 9236706Abstract: A surface-emitting laser apparatus includes: a surface-emitting laser element; and a driving apparatus supplying a modulation-driving current to the surface-emitting laser element. The modulation-driving current is intensity-modulated to vary across a value of a bias current. The number of lateral modes of laser oscillation of the surface-emitting laser element changes from one to three at maximum in accordance with a value of the modulation-driving current. Among changing currents at which number of the lateral modes of the laser oscillation of the surface-emitting laser element changes, if a first changing current is defined at which the number of the lateral mode of the laser oscillation changes from one to two, the driving apparatus supplies the modulation-driving current to the surface-emitting laser element. The modulation-driving current is set so that a value of the first changing current is not between the bias current and a maximum value of the modulation-driving current.Type: GrantFiled: December 1, 2014Date of Patent: January 12, 2016Assignee: FURUKAWA ELECTRIC CO., LTD.Inventors: Tomofumi Kise, Suguru Imai, Masaki Funabashi, Hitoshi Shimizu
-
Publication number: 20150131684Abstract: A surface-emitting laser apparatus includes: a surface-emitting laser element; and a driving apparatus supplying a modulation-driving current to the surface-emitting laser element. The modulation-driving current is intensity-modulated to vary across a value of a bias current. The number of lateral modes of laser oscillation of the surface-emitting laser element changes from one to three at maximum in accordance with a value of the modulation-driving current. Among changing currents at which number of the lateral modes of the laser oscillation of the surface-emitting laser element changes, if a first changing current is defined at which the number of the lateral mode of the laser oscillation changes from one to two, the driving apparatus supplies the modulation-driving current to the surface-emitting laser element. The modulation-driving current is set so that a value of the first changing current is not between the bias current and a maximum value of the modulation-driving current.Type: ApplicationFiled: December 1, 2014Publication date: May 14, 2015Applicant: FURUKAWA ELECTRIC CO., LTD.Inventors: Tomofumi KISE, Suguru IMAI, Masaki FUNABASHI, Hitoshi SHIMIZU
-
Patent number: 8861562Abstract: Provided is a vertical light emitting device comprising an upper multilayer reflective film and a lower multilayer reflective film that are formed facing each other and oscillate light; an intermediate layer that is formed below the upper multilayer reflective film and includes a layer having a different composition than the upper multilayer reflective film; and an electrode portion that is formed to sandwich the intermediate layer in a cross-sectional plane parallel to an oscillation direction of the light and to have a top end that is higher than a top surface of the intermediate layer. After the electrode portion is formed to sandwich the intermediate layer, the upper multilayer reflective film is layered on the intermediate layer.Type: GrantFiled: June 22, 2012Date of Patent: October 14, 2014Assignee: Furukawa Electric Co., Ltd.Inventors: Toshihito Suzuki, Keishi Takaki, Suguru Imai, Yasumasa Kawakita
-
Patent number: 8488644Abstract: A semiconductor laser element includes a first electrode, a second electrode, a first reflecting mirror, a second reflecting mirror, and a resonator. The resonator includes an active layer, a current confinement layer, a first semiconductor layer having a first doping concentration formed at a side opposite to the active layer across the current confinement layer, and a second semiconductor layer having a second doping concentration higher than the first doping concentration formed between the first semiconductor layer and the current confinement layer. The first electrode is provided to contact a part of a surface of the first semiconductor layer. The first semiconductor layer has a diffusion portion into which a component of the first electrode diffuses. The second semiconductor layer contacts the diffusion portion. The second semiconductor layer is positioned at a node of a standing wave at a time of laser oscillation of the semiconductor laser element.Type: GrantFiled: December 10, 2009Date of Patent: July 16, 2013Assignee: Furukawa Electric Co., Ltd.Inventors: Suguru Imai, Keishi Takaki, Norihiro Iwai, Kinuka Tanabe, Hitoshi Shimizu, Hirotatsu Ishii
-
Publication number: 20130010822Abstract: Provided is a vertical light emitting device comprising an upper multilayer reflective film and a lower multilayer reflective film that are formed facing each other and oscillate light; an intermediate layer that is formed below the upper multilayer reflective film and includes a layer having a different composition than the upper multilayer reflective film; and an electrode portion that is formed to sandwich the intermediate layer in a cross-sectional plane parallel to an oscillation direction of the light and to have a top end that is higher than a top surface of the intermediate layer. After the electrode portion is formed to sandwich the intermediate layer, the upper multilayer reflective film is layered on the intermediate layer.Type: ApplicationFiled: June 22, 2012Publication date: January 10, 2013Applicant: FURUKAWA ELECTRIC CO., LTD.Inventors: Toshihito SUZUKI, Keishi TAKAKI, Suguru IMAI, Yasumasa KAWAKITA
-
Patent number: 8306080Abstract: A surface emitting laser apparatus includes an arithmetic processing unit including an I/O unit for externally inputting an instruction and a core unit that performs an operation based on the instruction and outputs a differential voltage signal modulated with a predetermined amplitude according to a result of the operation, capacitors respectively arranged on output paths of the differential voltage signal, and a surface emitting laser device that is directly connected to the arithmetic processing unit via the capacitors. An I/O voltage and a core voltage are externally supplied to the I/O unit and the core unit, respectively. The arithmetic processing unit generates a driving voltage signal by superimposing the differential voltage signal with the core voltage commonly supplied as a bias voltage without stepping up or down the core voltage and without amplifying the differential voltage signal and supplies the driving voltage signal to the surface emitting laser device.Type: GrantFiled: April 20, 2011Date of Patent: November 6, 2012Assignee: Furukawa Electric Co., Ltd.Inventors: Keishi Takaki, Naoki Tsukiji, Suguru Imai
-
Publication number: 20110261852Abstract: A semiconductor laser element includes a first electrode, a second electrode, a first reflecting mirror, a second reflecting mirror, and a resonator. The resonator includes an active layer, a current confinement layer, a first semiconductor layer having a first doping concentration formed at a side opposite to the active layer across the current confinement layer, and a second semiconductor layer having a second doping concentration higher than the first doping concentration formed between the first semiconductor layer and the current confinement layer. The first electrode is provided to contact a part of a surface of the first semiconductor layer. The first semiconductor layer has a diffusion portion into which a component of the first electrode diffuses. The second semiconductor layer contacts the diffusion portion. The second semiconductor layer is positioned at a node of a standing wave at a time of laser oscillation of the semiconductor laser element.Type: ApplicationFiled: December 10, 2009Publication date: October 27, 2011Applicant: FURUKAWA ELECTRIC CO., LTDInventors: Suguru Imai, Keishi Takaki, Norihiro Iwai, Kinuka Tanabe, Hitoshi Shimizu, Hirotatsu Ishii
-
Publication number: 20110261846Abstract: A surface emitting laser apparatus includes an arithmetic processing unit including an I/O unit for externally inputting an instruction and a core unit that performs an operation based on the instruction and outputs a differential voltage signal modulated with a predetermined amplitude according to a result of the operation, capacitors respectively arranged on output paths of the differential voltage signal, and a surface emitting laser device that is directly connected to the arithmetic processing unit via the capacitors. An I/O voltage and a core voltage are externally supplied to the I/O unit and the core unit, respectively. The arithmetic processing unit generates a driving voltage signal by superimposing the differential voltage signal with the core voltage commonly supplied as a bias voltage without stepping up or down the core voltage and without amplifying the differential voltage signal and supplies the driving voltage signal to the surface emitting laser device.Type: ApplicationFiled: April 20, 2011Publication date: October 27, 2011Applicant: FURUKAWA ELECTRIC CO., LTD.Inventors: Keishi TAKAKI, Naoki TSUKIJI, Suguru IMAI
-
Patent number: 7907653Abstract: In the surface emitting laser, low threshold electric current and high-power output are achieved while maintaining single mode characteristics. The surface emitting laser comprises a layered structure formed on a GaAs substrate 10 is comprised of: a semiconductor lower DBR mirror 12, a cladding layer 14, a n-type contact layer 16, an active layer 18, an electric current constricting layer 20, a p-type cladding layer 22, a p-type contact layer 24, a phase adjusting layer 36 and a dielectric upper DBR mirror 28. The surface emitting laser should be formed such that the diameter X (?m) of the opening diameter of the previously mentioned electric current constricting layer 20 and diameter Y (?m) of the phase adjusting layer satisfy the following relation: X+1.9??Y?X+5.0? (wherein ? indicates oscillation wavelength (?m) of the surface emitting laser).Type: GrantFiled: February 18, 2009Date of Patent: March 15, 2011Assignee: Furukawa Electric Co., Ltd.Inventors: Norihiro Iwai, Keishi Takaki, Suguru Imai
-
Patent number: 7881353Abstract: Provided is a surface emitting laser element array of low cost and high reliability. The surface emitting laser element array has a substrate having a semiconductor of a first conduction type; and a plurality of surface emitting laser elements each having, above the substrate, an active layer sandwiched between a first conduction type semiconductor layer area and a second conduction type semiconductor layer area and disposed between a upper reflective mirror and a lower reflective mirror, the surface emitting laser elements being separated from each other by an electric separation structure formed having such a depth as to reach the substrate. The first conduction type semiconductor layer area is arranged between the substrate and the active layer.Type: GrantFiled: March 30, 2009Date of Patent: February 1, 2011Assignee: Furukawa Electric Co., Ltd.Inventors: Takeo Kageyama, Keishi Takaki, Naoki Tsukiji, Norihiro Iwai, Hitoshzi Shimizu, Yasumasa Kawakita, Suguru Imai
-
Publication number: 20090304036Abstract: In the surface emitting laser, low threshold electric current and high-power output are achieved while maintaining single mode characteristics. The surface emitting laser comprises a layered structure formed on a GaAs substrate 10 is comprised of: a semiconductor lower DBR mirror 12, a cladding layer 14, a n-type contact layer 16, an active layer 18, an electric current constricting layer 20, a p-type cladding layer 22, a p-type contact layer 24, a phase adjusting layer 36 and a dielectric upper DBR mirror 28. The surface emitting laser should be formed such that the diameter X (?m) of the opening diameter of the previously mentioned electric current constricting layer 20 and diameter Y (?m) of the phase adjusting layer satisfy the following relation: X+1.9??Y?X+5.0? (wherein ? indicates oscillation wavelength (?m) of the surface emitting laser).Type: ApplicationFiled: February 18, 2009Publication date: December 10, 2009Applicant: The Furukawa Electric Co., LTDInventors: Norihiro Iwai, Keishi Takaki, Suguru Imai
-
Publication number: 20090245312Abstract: Provided is a surface emitting laser element array of low cost and high reliability. The surface emitting laser element array has a substrate having a semiconductor of a first conduction type; and a plurality of surface emitting laser elements each having, above the substrate, an active layer sandwiched between a first conduction type semiconductor layer area and a second conduction type semiconductor layer area and disposed between a upper reflective mirror and a lower reflective mirror, the surface emitting laser elements being separated from each other by an electric separation structure formed having such a depth as to reach the substrate. The first conduction type semiconductor layer area is arranged between the substrate and the active layer.Type: ApplicationFiled: March 30, 2009Publication date: October 1, 2009Applicant: THE FURUKAWA ELECTRIC CO., LTDInventors: Takeo Kageyama, Keishi Takaki, Naoki Tsukiji, Norihiro Iwai, Hitoshzi Shimizu, Yasumasa Kawakita, Suguru Imai