Nec Corporation

Fujitsu Corporation

Nippon Telegraph and Telephone Corporation

Nec Platforms, Ltd.

Photonics Electronics Technology Research Association

Daisuke Okamoto

Junichi Fujikata

Kenichi Nishi

Jun Ushida

Keishi Ohashi

Tatsuya Usuki

Yasuyuki Suzuki

Masafumi Nakada

Toru Tatsumi

Yutaka Urino

Akihito Tanabe

Tai Tsuchizawa

Daisuke Shimada

Shuya Gonda

Seiichi Itabashi

Masahiro Oomine

Katsumi Kayama

An authentication system SYS comprises: an imaging unitcapable of generating an iris image IMG_I by capturing an image of an iris of an target P; and a display unitcapable of displaying information related to authentication of the target using the iris image, wherein at least a part of the imaging unit is disposed in a space SPadjacent to a back surfaceof the display unit, the back surface being located opposite a display surfacefor displaying the information, and the imaging unit is oriented in a direction different from a direction in which the target is present.

Authentication system and imaging apparatus

An optical receiving circuit which suppresses a characteristic deterioration due to a wiring between a PD and a TIA and a method for manufacturing the optical receiving circuit are provided. A optical receiving circuit () comprises a photodiode (), and a transimpedance amplifier () that supplies an electrical power source to the photodiode (). The characteristic impedance of a wiring between the anode of the photodiode () and the transimpedance amplifier () is higher than the characteristic impedance of a wiring between the cathode of the photodiode () and the transimpedance amplifier ().

Optical receiving circuit and method for manufacturing the same

An optical receiver circuit has a function of converting a differential optical signal into a differential current signal. The optical receiver circuit has a pair of light-receiving elements including first and second light-receiving elements operable to convert an optical signal into a current signal and a pair of signal lines. An anode of the first light-receiving element and a cathode of the second light-receiving element are connected to a first signal line of the pair of signal lines via first and second AC coupling capacitors, respectively. A cathode of the first light-receiving element and an anode of the second light-receiving element are connected to a second signal line of the pair of signal lines via third and fourth AC coupling capacitors, respectively. Differential signal currents are generated in the first and second signal lines in response to reception of differential optical signals inputted into the first and second light-receiving elements.

Optical receiver circuit

An opto-electric integrated circuit includes an optical waveguide formed using a portion of an insulation layer on a silicon substrate to form a lower clad and using a portion of a semiconductor layer formed on the insulation layer to form a core. The opto-electric integrated circuit also includes an optical device connected to the optical waveguide, an electrical circuit connected to the optical device, a mesa-shaped connection section interconnecting the optical device and the electrical circuit, and an electrically conductive film formed in a region at least containing a flank surface of the connection section. The electrically conductive film is grounded while contacting the silicon substrate.

Opto-electric integrated circuit and optical interposer

The present invention provides a photodetector which solves the problem of low sensitivity of a photodetector, an optical communication device equipped with the same, and a method for making the photodetector, and a method for making the optical communication device. The photodetector includes a substrate, a lower cladding layer arranged on the substrate, an optical waveguide arranged on the lower cladding layer, an intermediate layer arranged on the optical waveguide, a optical absorption layer arranged on the intermediate layer, a pair of electrodes arranged on the optical absorption layer, and wherein the optical absorption layer includes a IV-group or III-V-group single-crystal semiconductor, and the optical absorption layer absorbs an optical signal propagating through the optical waveguide.

Photodetector, optical communication device equipped with the same, method for making of photodetector, and method for making of optical communication device

A semiconductor light receiving element comprises: a substrate, a semiconductor layer of a first conductivity type formed on the substrate, a non-doped semiconductor light absorbing layer formed on the semiconductor layer of the first conductivity type, a semiconductor layer of a second conductivity type formed on the non-doped semiconductor light absorbing layer, and an electro-conductive layer formed on the semiconductor layer of the second conductivity type. A plurality of openings, periodically arrayed, are formed in a laminated body composed of the electro-conductive layer, the semiconductor layer of the second conductivity type, and the non-doped semiconductor light absorbing layer. The widths of the openings are less than or equal to the wavelength of incident light, and the openings pass through the electro-conductive layer and the semiconductor layer of the second conductivity type to reach the non-doped semiconductor light absorbing layer.

Semiconductor light receiving element and optical communication device

Provided is a high-speed and highly efficient semiconductor light-receiving element with small dependence on an incident light polarization direction. A semiconductor light-receiving element according to one aspect of the present invention includes a semiconductor layer including a light-absorbing layer, an MSM electrodethat is provided over the semiconductor layer, forms a Schottky junction with the semiconductor layer, and includes a slit-like opening, an anti-reflective filmformed over the semiconductor layer and the MSM electrode, and a Bragg reflection multilayer filmprovided to a lower part of the semiconductor layer. The MSM electrodeincludes a period capable of exciting surface plasmon to incident light of TM polarization, and obtains sufficient transmittance to the incident light of TE polarization.

Semiconductor light-receiving element, optical communication device, optical interconnect module, and photoelectric conversion method

In a waveguide path coupling-type photodiode, a semiconductor light absorbing layer and an optical waveguide path core are adjacently arranged. An electrode formed of at least one layer is installed in a boundary part of the semiconductor light absorbing layer and the optical waveguide path core. The electrodes are arranged at an interval of (1/100)&#x3bb; to &#x3bb; [&#x3bb;: wavelength of light transmitted through optical waveguide path core]. At least a part of the electrodes is embedded in the semiconductor light absorbing layer. Embedding depth from a surface of the semiconductor light absorbing layer is a value not more than &#x3bb;/(2 ns) [ns: refractive index of semiconductor light absorbing layer]. At least one layer of the electrode is constituted of a material which can surface plasmon-induced.

Waveguide path coupling-type photodiode

A semiconductor device comprises a semiconductor layer having a semiconductor integrated circuit, which is for processing an electrical signal, on a semiconductor substrate and an optical interconnect layer for transmitting an optical signal are joined. Control of modulation of the optical signal transmitted in the optical interconnect layer is performed by an electrical signal from the semiconductor layer, and an electrical signal generated by reception of light in the optical interconnect layer is transmitted to the semiconductor layer. The optical interconnect layer is disposed on the underside of the semiconductor substrate.

Semiconductor device

Provided is a semiconductor optical interconnection device capable of transmitting signals between laminated semiconductor chips in a structure where semiconductor chips highly functionalized by being bonded to an optical interconnection chip are laminated. The semiconductor optical interconnection device includes a semiconductor chipand an optical interconnection chip. The optical interconnection chipincludes an optical element formed thereon (for instance, a photo-sensitive element, a luminous element, or an optical modulator) which has a function relating to signal conversion between light and electricity. The semiconductor chipincludes a transmission section(for instance, a coil or an inductor) to transmit signals in a non-contact manner, and a connection section(for instance, a bump) to electrically connect with the optical element.

Semiconductor optical interconnection device and semiconductor optical interconnection method

The lattice mismatching between a Ge layer and a Si layer is as large as about 4%. Thus, when the Ge layer is grown on the Si layer, penetration dislocation is introduced to cause leakage current at the p-i-n junction. Thereby, the photo-detection sensitivity is reduced, and the reliability of the element is also lowered. Further, in the connection with a Si waveguide, there are also problems of the reflection loss due to the difference in refractive index between Si and Ge, and of the absorption loss caused by a metal electrode. In order to solve said problems, according to the present invention, there is provided a vertical type pin-SiGe photodiode having a structure which is embedded in a groove formed in a part of a Si layer, in which a p-type or n-type doped layer is formed in a lower section of the groove, and in which a i-SiGe layer having a rectangular shape or a reverse tapered shape is formed on a layered structure formed by laminating a i-Si layer and a SiGe buffer layer on the lower section and the side wall of the groove. Further, in an optical connection section with a Si waveguide, impedance matching is effected by the layered structure composed of the i-Si layer and the SiGe buffer layer, and an upper metal layer is separated therefrom so that a poly-Si bridge structure is employed to electrically connect the upper metal layer therewith.

SiGe photodiode

A photodiode includes: an upper spacer layer including a semiconductor transparent to incident light; a metal periodic structure provided on the upper spacer layer and arranged to induce surface plasmon, the metal periodic structure including first and second electrodes including portions arranged alternately on the upper spacer layer; a light absorption layer formed under the upper spacer layer and including a semiconductor having a refractive index higher than that of the upper spacer layer; and a lower spacer layer formed under the light absorption layer and having a refractive index smaller than that of the light absorption layer. Each of the first and second electrodes forms a Schottky barrier junction with the upper spacer layer.

Photodiode

Provided is a small-size optical phase modulation element and an optical modulator using it. The optical phase modulation element includes a Plasmon waveguide having a clad made of a metal material having a complex dielectric constant having a negative real part in the used wavelength and a core formed by a dielectric metal material having a complex dielectric constant having a positive real part in the used wavelength. The Plasmon waveguide is connected to an optical waveguide including a clad and a core both having a complex dielectric constant having a positive real part. The core of the Plasmon waveguide and the core of the optical waveguide are formed, at least partially, of the same semiconductor material. The Plasmon waveguide has a function to phase-modulate the incident light when voltage is applied.

Growing community of inventors

Tokyo, Japan

Daisuke Okamoto