Patents Assigned to NTT Electronics Corporation
-
Publication number: 20140183677Abstract: The present invention is intended to provide a compact and simple optical semiconductor device that reduces crosstalk (leakage current) between light receiving elements. According to the present invention, since a back surface electrode is a mirror-like thin film, crosstalk to an adjacent light receiving element can be suppressed, thereby reducing a detection error of a light intensity. By disposing a patterned back surface electrode or by disposing an ohmic electrode at the bottom of an insulating film over the whole back surface, contact resistance on the back surface can be reduced. By using the optical semiconductor elements with a two-dimensional arrangement and by using a mirror-like thin film as the back surface electrode, crosstalk can be reduced. By accommodating the optical semiconductor elements in the housing in a highly hermetic condition, the optical semiconductor elements can be protected from an external environment.Type: ApplicationFiled: March 4, 2014Publication date: July 3, 2014Applicants: NTT Electronics Corporation, Nippon Telegraph and Telephone CorporationInventors: Yoshiyuki Doi, Yoshifumi Muramoto, Takaharu Ohyama
-
Patent number: 8764313Abstract: An optical connector plug to be inserted to an adapter, is arranged such that a pair of engaging parts for expanding an elastic locking piece provided on a side of the adapter by a taper part and locking it with a step part is provided on a tip part of a plug frame which is a body of the plug; a locking releasing piece movable along an insertion-extraction direction is provided between the pair of engaging parts; a taper part for releasing a locking action of the elastic locking piece when extracting the plug is provided at a rear end of the locking releasing piece; and the taper part of the engaging parts has such a shape that the connecting stress is not lowered before being locked when inserting the plug.Type: GrantFiled: November 17, 2010Date of Patent: July 1, 2014Assignees: NTT Electronics Corporation, Nippon Telegraph and Telephone Corporation, Honda Tsushin Kogyo Co. LtdInventors: Koichi Arishima, Yoshi Kurosawa, Fumiaki Hanawa, Ryo Nagase, Toshiaki Eguchi, Naohide Goto
-
Patent number: 8754445Abstract: A layer in which the potential level difference normally unrequired for device operation is generated is positively inserted in a device structure. The potential level difference has such a function that even if a semiconductor having a small bandgap is exposed on a mesa side surface, a potential drop amount of the portion is suppressed, and a leakage current inconvenient for device operation can be reduced. This effect can be commonly obtained for a heterostructure bipolar transistor, a photodiode, an electroabsorption modulator, and so on. In the photodiode, since the leakage current is alleviated, the device size can be reduced, so that in addition to improvement of operating speed with a reduction in series resistance, it is advantageous that the device can be densely disposed in an array.Type: GrantFiled: January 20, 2012Date of Patent: June 17, 2014Assignees: NTT Electronics Corporation, Nippon Telegraph and Telephone CorporationInventors: Tadao Ishibashi, Seigo Ando, Yoshifumi Muramoto, Toshihide Yoshimatsu, Haruki Yokoyama
-
Patent number: 8744223Abstract: The present invention provides an array-type photo module including a filter, which, in each channel, transmits therethrough a portion of emitted light from an incident optical fiber on the opposite side of a gradient-index lens array and reflects another portion of the emitted light from the incident optical fiber toward the gradient-index lens array, and a light-shielding member which is arranged on the opposite side of the filter from the gradient-index lens array, so as to be spaced from the filter and, in each channel, has an opening passing therethrough transmitted light from the filter on the opposite side of the filter. The array-type photo module is easily and inexpensively manufactured, and may be used in a high-density array, with low crosstalk.Type: GrantFiled: March 1, 2012Date of Patent: June 3, 2014Assignees: Kitanihon Electric Cable Co., Ltd., NTT Electronics CorporationInventors: Yuto Yamashita, Keiichi Sasaki, Etsuo Ogino, Yasuaki Tamura, Yuji Akahori, Yuichi Suzuki
-
Publication number: 20140139536Abstract: A first look-up table (10) outputs a result of dividing a horizontal component of a pixel address in the block by number of pixels in a horizontal component of the cell. A second look-up table (12) outputs a result of dividing a vertical component of a pixel address in the block by number of pixels in a vertical component of the cell. A third look-up table (14) outputs a residue as a result of dividing a horizontal component of a pixel address in the block by number of pixels in a horizontal component of the cell. A fourth look-up table (16) outputs a residue as a result of dividing a vertical component of a pixel address in the block by number of pixels in a vertical component of the cell. The output values of the first and second look-up tables (10,12) are addresses of the cell for burst access to the memory. The output values of the third and fourth look-up tables (14,16) are used as pixel addresses in the cell.Type: ApplicationFiled: March 10, 2011Publication date: May 22, 2014Applicant: NTT ELECTRONICS CORPORATIONInventors: Yasuhiro Yamada, Norihiko Nagai
-
Patent number: 8729602Abstract: An APD is provided with a semi-insulating substrate, a first mesa having a first laminate constitution in which a p-type electrode layer, a p-type light absorbing layer, a light absorbing layer with a low impurity concentration, a band gap inclined layer, a p-type electric field control layer, an avalanche multiplier layer, an n-type electric field control layer, and an electron transit layer with a low impurity concentration are stacked in this order on a surface of the semi-insulating substrate, a second mesa having an outer circumference provided inside an outer circumference of the first mesa as viewed from the laminating direction and having a second laminate constitution in which an n-type electrode buffer layer and an n-type electrode layer are stacked in this order on a surface on the electron transit layer side of the first mesa, and in the APD, a total donor concentration of the n-type electric field control layer is lower than a total acceptor concentration of the p-type electric field control layeType: GrantFiled: September 1, 2011Date of Patent: May 20, 2014Assignees: NTT Electronics Corporation, Nippon Telegraph and Telephone CorporationInventors: Tadao Ishibashi, Seigo Ando, Masahiro Nada, Yoshifumi Muramoto, Haruki Yokoyama
-
Patent number: 8721191Abstract: In an optical component configured to fix to a mount an optical device chip in which waveguide type optical devices having different thermal expansion coefficients are butt-jointed, deterioration in reliability due to thermal stress is suppressed. The optical component (300) comprises an optical device chip (310) including an LN waveguide (311), a first PLC waveguide (312), a second PLC waveguide (313), and a fiber alignment member (314), a mount (320), and optical fibers (330). Each of connection faces between the first PLC waveguide and the fiber alignment member is configured as an tilted structure, and each of connection faces between the LN waveguide, and the first and second PLC waveguides is configured as a right-angled structure. In the right-angled structure, the connection faces are connected by an adhesive having a lower Young's modulus than that of an adhesive used on the connection faces of the tilted structure.Type: GrantFiled: August 2, 2011Date of Patent: May 13, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Motohaya Ishii, Takashi Yamada, Yoshiyuki Doi, Takashi Saida, Ken Tsuzuki, Takashi Goh, Hiroshi Yamazaki, Shinji Mino, Takao Fukumitsu, Atsushi Murasawa, Fumihiro Ebisawa, Hiroshi Terui, Tomoyo Shibazaki, Yuichi Kikuchi
-
Patent number: 8704322Abstract: The present invention is intended to provide a compact and simple optical semiconductor device that reduces crosstalk (leakage current) between light receiving elements. According to the present invention, since a back surface electrode is a mirror-like thin film, crosstalk to an adjacent light receiving element can be suppressed, thereby reducing a detection error of a light intensity. By disposing a patterned back surface electrode or by disposing an ohmic electrode at the bottom of an insulating film over the whole back surface, contact resistance on the back surface can be reduced. By using the optical semiconductor elements with a two-dimensional arrangement and by using a mirror-like thin film as the back surface electrode, crosstalk can be reduced. By accommodating the optical semiconductor elements in the housing in a highly hermetic condition, the optical semiconductor elements can be protected from an external environment.Type: GrantFiled: January 23, 2012Date of Patent: April 22, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Yoshiyuki Doi, Yoshifumi Muramoto, Takaharu Ohyama
-
Patent number: 8699832Abstract: A light-shielding portion (10) shields the light spot of output light output toward a shunt position ? by a projecting portion (12). Hence, the output light output toward the shunt position ? does not travel to an output port (111). This allows to prevent crosstalk.Type: GrantFiled: March 29, 2010Date of Patent: April 15, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Nobuaki Matsuura, Koichi Hadama, Etsu Hashimoto, Yuzo Ishii, Mitsuo Usui, Tohru Matsuura, Toshiki Nishizawa, Yuji Mitsuhashi
-
Patent number: 8666312Abstract: A signal electrode (11A) and a ground electrode (11B) are disposed respectively on surfaces of a case (10). In this way, the signal electrode (11A) and the ground electrode (11B) do not come into contact with any electric component, such as a transmission circuit (21), disposed inside the case (10), and thus a reduction in an electric field (Ec) induced in an electric-field transmission medium can be prevented. In addition, a certain distance between the signal electrode (11A) and the ground electrode (11B) is kept, and thus a reduction in the electric field (Ec) induced in the electric-field transmission medium can be prevented. Furthermore, the contactability between the signal electrode (11A) and the electric-field transmission medium is improved, and thus the electric field (Ec) induced in the electric-field transmission medium can be increased.Type: GrantFiled: March 21, 2008Date of Patent: March 4, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Ryusuke Kawano, Katsuyuki Ochiai, Mitsuru Shinagawa, Yuichi Kado, Takuji Harada, Hideyuki Okamoto, Ryoichi Matsumoto
-
Patent number: 8660151Abstract: An encoding apparatus 2 includes: an encoding unit 21 that encodes and multiplexes a video signal V2, an audio signal A2 and a data signal D2 to be given to the encoding apparatus 2; a timer 22 that outputs time information T2; a timer adjusting unit 23 that adjusts the timer 22 so that the time information T2 and time information T1 within a multiplexed stream S1 outputted from an encoding apparatus 1 are synchronized with each other; and a multiplexing unit 24 that multiplexes the multiplexed stream S1, an encoded stream S21 outputted from the encoding unit 21 and the time information T2, and outputs the resultant multiplexed stream and information as output of the encoding apparatus 2. Third and subsequent encoding apparatus are configured to have the same configuration as that of the encoding apparatus 2.Type: GrantFiled: September 22, 2010Date of Patent: February 25, 2014Assignee: NTT Electronics CorporationInventors: Hidetoshi Suzuki, Kazufumi Watanabe, Eiko Sone, Masayoshi Kubozono, Masashi Takada
-
Publication number: 20140023333Abstract: An optical component has first and second planar lightwave circuits. The first and second planar lightwave circuits are aligned and jointed such that the position of an i-th optical waveguide (where i is an integer greater than or equal to 1 and less than or equal to n) of the first planar lightwave circuit and that of an i-th optical waveguide of the second planar lightwave circuit are matched on a joint interface. An angle formed by the i-th optical waveguide of the first planar lightwave circuit and a normal of the interface is configured to vary in accordance with a value of i within a range satisfying the Snell's law.Type: ApplicationFiled: April 18, 2012Publication date: January 23, 2014Applicants: NTT Electronics Corporation, Nippon Telegraph and Telephone CorporationInventors: Motohaya Ishii, Takashi Saida, Hiroshi Terui, Tomoyo Shibazaki, Yuichi Kikuchi
-
Patent number: 8625943Abstract: Excess optical power in a waveguide device is appropriately terminated. According to one embodiment of the present invention, the waveguide device comprises a termination structure filled with a light blocking material for terminating light from the end section of a waveguide. This termination structure can be formed by forming a groove on an optical waveguide by removing the clad and core, and filling the inside of that groove with a material attenuating the intensity of the light (light blocking material). In this manner, light that enters into the termination structure is attenuated by the light blocking material, and influence on other optical devices as a crosstalk component can be suppressed. With such termination structure, not only the influence on optical devices integrated on the same substrate, but also the influence on other optical devices directly connected to that substrate can be suppressed.Type: GrantFiled: May 26, 2009Date of Patent: January 7, 2014Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Shunichi Soma, Takashi Goh, Yasuaki Hashizume, Masahiro Yanagisawa, Takanori Ishikawa, Mitsuru Nagano, Atsushi Murasawa, Masayuki Okuno
-
Patent number: 8615146Abstract: A planar optical waveguide including a clad layer, an optical waveguide having a core embedded in the clad layer; and a groove formed in the clad layer and having a reflection interface for totally reflecting a leaked light leaked from the optical waveguide to the clad layer. Since the reflection interface for totally reflecting the leaked light is formed in the clad layer, the leaked light is prevented from entering into the tap coupler, and the variation of the branching ratio can be reduced.Type: GrantFiled: July 29, 2009Date of Patent: December 24, 2013Assignee: NTT Electronics CorporationInventors: Mitsuru Nagano, Akira Himeno, Masayuki Okuno, Masahiko Naito, Akihito Doi, Daisuke Ogawa, Akira Nagai
-
Publication number: 20130313608Abstract: A layer in which the potential level difference normally unrequired for device operation is generated is positively inserted in a device structure. The potential level difference has such a function that even if a semiconductor having a small bandgap is exposed on a mesa side surface, a potential drop amount of the portion is suppressed, and a leakage current inconvenient for device operation can be reduced. This effect can be commonly obtained for a heterostructure bipolar transistor, a photodiode, an electroabsorption modulator, and so on. In the photodiode, since the leakage current is alleviated, the device size can be reduced, so that in addition to improvement of operating speed with a reduction in series resistance, it is advantageous that the device can be densely disposed in an array.Type: ApplicationFiled: January 20, 2012Publication date: November 28, 2013Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT ELECTRONICS CORPORATIONInventors: Tadao Ishibashi, Seigo Ando, Yoshifumi Muramoto, Toshihide Yoshimatsu, Haruki Yokoyama
-
Patent number: 8593223Abstract: In an automatic gain control circuit, a peak detection circuit detects and outputs the peak voltage of an output signal from a variable gain circuit. An average value detection/output amplitude setting circuit detects the average value voltage of an output signal from the variable gain circuit, and outputs a calculated voltage. An amplification circuit controls the gain of the variable gain circuit by amplifying the difference between the output voltages of the peak detection circuit and average value detection/output amplitude setting circuit. The number of base-emitter junctions of transistors on a path in the peak detection circuit from input ports which receive output signals from the variable gain circuit to an output port which outputs a voltage to the amplification circuit is equal to the number of base-emitter junctions of transistors on a path in the average value detection/output amplitude setting circuit.Type: GrantFiled: June 19, 2012Date of Patent: November 26, 2013Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Kimikazu Sano, Hiroyuki Fukuyama, Hideyuki Nosaka, Makoto Nakamura, Koichi Murata, Masatoshi Tobayashi, Yasunobu Inabe, Eisuke Tsuchiya
-
Patent number: 8593201Abstract: In a signal output circuit, an input buffer externally receives a single-phase switching instruction signal to switch a state of the output circuit a shutdown disable state or a shutdown enable state, and converts and outputs the single-phase switching instruction signal into a differential switching instruction signal. A generation control circuit outputs a generation control signal for controlling generation of a control voltage in the control voltage generation circuit based on the differential switching instruction signal. A control voltage generation circuit outputs the control voltage upon changing a value of the control voltage in accordance with a logic of the single-phase switching instruction signal. An output circuit externally receives a differential input signal, outputs a differential output signal upon impedance-converting the differential input signal, and switches between the shutdown disable state and the shutdown enable state of the differential input signal.Type: GrantFiled: June 19, 2012Date of Patent: November 26, 2013Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Kimikazu Sano, Hiroyuki Fukuyama, Hideyuki Nosaka, Makoto Nakamura, Koichi Murata, Masatoshi Tobayashi, Eisuke Tsuchiya
-
Patent number: 8575650Abstract: An electron injected APD with an embedded n electrode structure in which edge breakdown can be suppressed without controlling the doping profile of an n-type region of the embedded n electrode structure with high precision. The APD comprising a buffer layer with a low ionization rate is inserted between an n electrode connecting layer and an avalanche multiplication layer. Specifically, the APD is an electron injected APD in which an n electrode layer, the n electrode connecting layer, the buffer layer, the avalanche multiplication layer, an electric field control layer, a band gap gradient layer, a low-concentration light absorbing layer, a p-type light absorbing layer, and a p electrode layer are sequentially stacked, and a light absorbing portion that includes at least the low-concentration light absorbing layer and the p-type light absorbing layer forms a mesa shape.Type: GrantFiled: December 11, 2009Date of Patent: November 5, 2013Assignees: NTT Electronics Corporation, Nippon Telegraph and Telephone CorporationInventors: Tadao Ishibashi, Seigo Ando, Yoshifumi Muramoto, Fumito Nakajima, Haruki Yokoyama
-
Patent number: 8571037Abstract: An optical digital transmission system of the present invention newly defines one second negative stuff byte in an overhead area for accommodation of the client signals with multiplexing into the OTU frame, newly defines one third positive stuff byte in a corresponding tributary slot in a payload area for accommodation of client signals with multiplexing, newly defines stuff control bits that is used for decision of the use of the second negative stuff byte and the third positive stuff byte in three different places in the overhead area for client signal accommodation with multiplexing, performs control by using the newly defined stuff control bits when accommodation of the client signal with the third positive stuff byte or the second negative stuff byte is required, and performs stuff control without using the newly defined stuff control bits when accommodation of the client signal by the third positive stuff byte and the second negative stuff byte is not required.Type: GrantFiled: November 13, 2009Date of Patent: October 29, 2013Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Shigeki Aisawa, Masahito Tomizawa, Yutaka Miyamoto, Yoshiaki Kisaka, Yasuyuki Endo, Katsuyoshi Miura, Kazuhito Takei
-
Patent number: 8569674Abstract: A low cost photocurrent monitoring circuit is provided. A photocurrent monitoring circuit, which performs monitoring by converting photocurrents output from a plurality of photodiodes (PD1 to PDn) into voltage, includes: a multiplexer circuit (MUX) for selecting one of input terminals to establish a connection of the selected input terminal to an output terminal, wherein the photodiodes (PD1 to PDn) are respectively connected to the input terminals; and an amplifier (LA) for converting a photocurrent which flows from a selected photodiode via the multiplexer circuit (MUX) into a voltage, and for outputting the voltage.Type: GrantFiled: August 21, 2007Date of Patent: October 29, 2013Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Ryosuke Saito, Hisanobu Tanigawa, Takashi Goh, Ryoichi Kasahara