Ntt Electronics Corporation

Nippon Telegraph and Telephone Corporation

Keiichi Morita

Kazumi Shimizu

Yusuke Nasu

Koji Kawashima

Kouji Kawashima

Tomoharu Niitsu

Kenya Suzuki

Shunichi Soma

Hiroshi Terui

Fumito Nakajima

Fumihiro Ebisawa

Atsushi Murasawa

Hiroki Kawashiri

Akira Komiyama

A light shielding structure of an optical circuit of the present invention uses a part of the structure of the light reception element itself to suppress stray light. A stepped electrode that covers an upper surface and side surface of a first semiconductor layer constituting a light absorption portion of the light reception element is formed at a height substantially equal to that of an optical waveguide in the optical circuit, and the light absorption portion of the light reception element is shielded from stray light by a wall-shaped or column-shaped wiring electrode extending substantially perpendicularly to a surface layer of the optical circuit. The light shielding structure of the present invention uses a part of the configuration of the light reception element, is formed integrally with the light reception element, and also has an aspect of the invention of the light reception element.

Light reception element and light shielding structure for optical circuit

A technique that does not increase the circuit size, does not make the circuit design and manufacturing difficult, and can reduce insertion loss when light enters from a slab waveguide toward an arrayed waveguide or when the light enters from the arrayed waveguide toward the slab waveguide. An optical waveguide provided with a slab waveguide in which a grating is formed therein at a distance from an end, and an arrayed waveguide whose end is connected to an end of the slab waveguide at a position where a constructive interference portion of a self-image of the grating is formed. An arrayed waveguide grating provided with a first input/output waveguide, the above-mentioned optical waveguide where an end of the slab waveguide on the opposite side of the arrayed waveguide is connected to an end of the first input/output waveguide, a second slab waveguide connected to an end of the arrayed waveguide on the opposite side of the slab waveguide, and a second input/output waveguide connected to an end of the second slab waveguide on the opposite side of the arrayed waveguide.

Optical waveguide and arrayed waveguide grating

This optical waveguide is provided with a slab waveguide in which a grating is formed, an arrayed waveguide connected to a position where a constructive interference portion of a self-image of the grating is formed, and a refractive index change region which is formed between the slab waveguide and the arrayed waveguide, in which an average value of a refractive index in a refractive index distribution in a direction substantially vertical to a light propagation direction is averagely increased from the slab waveguide toward the arrayed waveguide, and in which an average value of the refractive index in a refractive index distribution in a direction substantially parallel to the light propagation direction is increased at a central axis of the arrayed waveguide.

A microlens array, which maintains high positional accuracy with respect to an optical circuit such as a waveguide and facilitates connection operation, and an optical transmission component including the microlens array. Solution The microlens array is provided with a plurality of microlenses arranged in an array structure and having the same length in the optical axis direction and optical fibers for alignment arranged at both ends of the array structure so that the optical axis is parallel to the optical axis of the microlens and having a length in the optical axis direction the same as the length of the microlens and a guided mode diameter smaller than an aperture of the microlens.

Microlens array and optical transmission component

An optical waveguide provided with a slab waveguide, which has a plurality of phase gratings arranged at a distance from each other in a direction substantially parallel to a light propagation direction and diffracting propagated light and a plurality of interference regions arranged alternately to the plurality of phase gratings in the direction substantially parallel to the light propagation direction and interfering the light diffracted by the plurality of phase gratings, and an arrayed waveguide whose end is connected to an end of the slab waveguide at a position of a constructive interference portion of a self-image formed by the plurality of phase gratings as an integrated phase grating.

Growing community of inventors

Yokohama, Japan

Keiichi Morita