Nippon Telegraph and Telephone Corporation

Ntt Electronics Corporation

Toshimi Kominato

Yasuyuki Inoue

Yasuhiro Hida

Akio Sugita

Mikitaka Itoh

Norio Takato

Yasumori Ohmura

A Y branch circuit according to the present invention includes; a under clad; a circuit core, formed on the under clad and having a main core and two branch cores, connected to the main core, and an over clad that embeds the circuit core. The main core and the two branch cores are connected across an interval. The two branch cores have a width-to-height ratio of 50% to 150% and have a gap, at the main core end, that is narrower at the over clad side than at the under clad side.

Y branch circuit and method for manufacturing the same

An optical waveguide circuit is provided that can reduce or eliminate polarization dependence by reducing or eliminating birefringence. A substrate consists of a silicon substrate, and a cladding and a core are composed of silica-based glass. The core has a multilayer structure composed of a few types of layers with different refractive indices such as first core layers and second core layers stacked in the direction parallel to the substrate. As for the birefringence of the waveguide, the geometrical birefringence caused by the multilayer structure is canceled out by the other birefringence, thereby being able to reduce or eliminate the birefringence of the waveguide.

Optical waveguide circuit

Growing community of inventors

Atsugi, Japan

Toshimi Kominato