Nippon Telegraph and Telephone Corporation

Katsumi Katoh

Masao Kawachi

Masayuki Okuno

Kuniharu Kato

Kaname Jinguji

The present invention enables waveguides to be simply laid out, wherein the correlationship between a curvilinear graphic connecting two points together and the positions of these two points is specified beforehand and stored in a RAM in the form of rule of virtual path generation, when a mouse is used to specify the connection terminals of two blocks on a display screen, a CPU receives an instruction for generation of virtual paths, and the CPU then references the rule of virtual path generation to automatically generate a virtual path connecting the connection terminals of the two blocks and to draw it on the display screen.

Circuit design system, image processing method and medium of the circuit design system

A waveguide-type optical matrix switch including as its switching element a Mach-Zehnder interferometer which includes two directional couplers and an optical phase shifter. The two directional couplers are arranged by placing two optical waveguides in close proximity at two positions on a substrate, and have an identical coupling ratio. The optical phase shifter is disposed over at least one of the two optical waveguides between the directional couplers. The two optical waveguides have an effective optical path length difference of half a wavelength of a light signal between the two directional couplers, and are intersected in the optical switch element. The waveguide-type optical matrix switch is little affected by fabrication errors in the coupling ratio of the directional couplers, and superior in the extinction ratio.

Growing community of inventors

Ibaraki, Japan

Katsumi Katoh