Nippon Telegraph and Telephone Corporation

Yoshiho Maeda

Hiroshi Fukuda

Toru Miura

Fumito Nakajima

Tatsuro Hiraki

Kiyofumi Kikuchi

Atsushi Kanda

Yoshifumi Muramoto

Kotaro Takeda

Kimikazu Sano

Toshihide Yoshimatsu

Takuma Aihara

In an embodiment, an optical inspection circuit includes: an optical modulator comprising an optical waveguide on a substrate, the optical waveguide having a core comprising a semiconductor; a first input waveguide optically connected to the optical modulator, the first input waveguide having a core comprising the semiconductor; an output waveguide optically connected to the optical modulator, the output waveguide having a core comprising the semiconductor; a photodiode on the substrate in a vicinity of the optical modulator; a wire electrically connecting the optical modulator and the photodiode; and a second input waveguide optically connected to the photodiode, the second input waveguide having a core comprising the semiconductor.

Optical inspection circuit and optical inspection method

A light receiving device includes, on a substrate, a Si waveguide core provided in a dielectric layer, a first i-type waveguide clad, an i-type core layer, a second i-type waveguide clad, p-type layers disposed on one side of a side surface of a layered structure in a light waveguide direction, the layered structure including the first i-type waveguide clad, the i-type core layer, and the second i-type waveguide clad, n-type layers disposed on the other side, and an electrode on a surface of each of the n-type layers. A width of the Si waveguide core is set to be able to suppress absorption of light in a vicinity of an input edge of the i-type core layer.

Light-receiving device

There is provided an optical waveguide constituted by a core made of a semiconductor and formed on a substrate. A grating coupler is provided at one end of the optical waveguide. Further, a reflecting portion formed on the optical waveguide by being optically coupled to the optical waveguide is provided at the other end of the optical waveguide. The optical waveguide constituted by the core includes a light intensity modulation unit that modulates an intensity of guided light in the optical waveguide. The light intensity modulation unit is constituted by a variable optical attenuator.

Optical circuit for alignment and optical alignment method

An alignment optical circuit includes: a plurality of grating couplers that are formed on a substrate and arranged on a line; a plurality of optical waveguides that are connected to the plurality of grating couplers, respectively. Further, the alignment optical circuit includes an optical sensor that is formed on the substrate and measures optical intensity at a first light-receiving spot and a second light-receiving spot on a line along an arrangement direction of the plurality of grating couplers.

Aligning optical circuit and aligning method

A stage, electric probes, an optical probe, an electric measurement device, an optical measurement device, and a first positioning mechanism are provided. The stage includes a second positioning mechanism that changes relative positional relationship between the electric probes and an electric connection portion of each of the optical elements. The electric probes electrically connect the electric measurement device and each of the optical elements. The optical probe optically connects the optical measurement device and each of the optical elements. The first positioning mechanism changes relative positional relationship between the optical probe and an optical connection portion of each of the optical elements.

Inspection device and method

Provided is a photodetector which can be manufactured in a standard process of a mass-produced CMOS foundry. The photodetector includes a silicon (Si) substrate; a lower clad layer; a core layer including a waveguide layer configured to guide signal light, and including a first Si slab doped with first conductive impurity ions and a second Si slab doped with second conductive impurity ions; a germanium (Ge) layer configured to absorb light and including a Ge region doped with the first conductive impurity ions; an upper clad layer; and electrodes respectively connected to the first and second Si slabs and the Ge region. A region of the core layer sandwiched between the first Si slab and the second Si slab operates as an amplification layer.

Photodetector

Plural grating couplers having grating conditions different from each other and plural optical waveguides respectively connected with the plural grating couplers are included. The plural grating couplers have the same arraying directions of gratings. Further, each of the plural grating couplers has a different grating interval as a grating condition. Further, plural reflection units respectively provided to the plural optical waveguides are included.

Optical circuit for alignment

An embodiment optical test circuit includes a first optical circuit and a second optical circuit formed on a substrate, an input optical waveguide optically connected to the first optical circuit and the second optical circuit, and an output optical waveguide optically connected to the first optical circuit and the second optical circuit. The optical test circuit also includes a light emitting diode optically connected to the input optical waveguide, and a photodiode optically connected to the output optical waveguide.

Optical test circuit

The misalignment between light reception lenses and light reception elements in a lens integrated light reception element for converting a plurality of optical signals with different wavelengths into electric signals is easily inspected. The lens integrated light reception element includes one or more light reception lenses that receive the optical signals, one or more light reception elements each disposed on a main axis of the light reception lens and converting the optical signal into the electric signal, one or more inspection pinholes through which illumination light passes, and one or more inspection lenses each including a main axis parallel to the main axis of the light reception lens and converging the illumination light having passed through the inspection pinhole.

Lens-integrated light-receiving element and method of examining same

An optical waveguide in which a grating coupler is formed, a first pattern region arranged to surround the grating coupler, and a second pattern region arranged to surround the grating coupler are included. The first pattern region and the second pattern region are arranged adjacently. In a periphery of the grating coupler, the first pattern region is formed in a region continuous in a circumferential direction. Similarly, in the periphery of the grating coupler, the second pattern region is formed in a region continuous in the circumferential direction.

An optical inspection circuit includes an optical circuit to be inspected formed on a substrate, an input optical waveguide optically connected to the optical circuit, and an output optical waveguide optically connected to the optical circuit. The input optical waveguide is connected with a grating coupler for input. The grating coupler is connected with the input optical waveguide via a spot size conversion unit. The output optical waveguide is optically connected with a photodiode.

Optical inspection circuit

A photodiode including a p-type region and an n-type region formed in a core of a grating coupler is provided. The p-type region and the n-type region are each formed as a region having a rectangular shape extending in an array direction of a grating as seen in plan view and are arranged in a direction orthogonal to the array direction of the grating and parallel to a plane of a substrate. A plurality of the p-type regions and a plurality of the n-type regions are formed and alternately arranged.

A light receiving element includes a first substrate, a photodiode formed on a main surface of the first substrate, and a second substrate constituted by a semiconductor and adhered to a rear surface side of the first substrate by an adhesive layer formed from a resin adhesive. A light receiving element according to an embodiment includes a lens that is formed on the side of an adhesion surface of the second substrate, has a convex surface, and is disposed in a light receiving region of the photodiode. The light receiving side of the photodiode is oriented toward the side of the first substrate. The lens is disposed so that the convex surface thereof is oriented toward the side of a light receiving surface of the photodiode.

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Tokyo, Japan

Yoshiho Maeda