LIGHT WAVE AND SUBMILLIMETER-MILLIMETER WAVE PLANAR CIRCUIT TYPE CIRCULATOR USING MAGNETOOPTIC MATERIAL THIN FILM AND FERROMAGNETIC THIN PLATE

摘要

PURPOSE:To attain two-way communication by arranging a planar circuit disk resonator processed by a magnetooptical material thin film and a planar circuit waveguide able to couple at least three external fiber lines with the resonator in rotation symmetry, and applying an external bias magnetic field in parallel with a vertical common axis. CONSTITUTION:Magnetooptical material thin film is formed by vapor-depositing a single crystal such as a YIG or a Bi-YIG including its additives on a GGG (Gallium- Gadorinium Garnet) substrate. A planar circuit type light wave circulator is formed via process such as etching through the use a micro processing device. Moreover, an external bias magnetic field HDC is applied perpendicularly to a film face, a light wave from a glass fiber is made incident in a resonance part 10 through a #1 coupling line 11, in which the wave is converted into left and right rotatory electromagnetic waves. Then the incident light wave is propagated in a direction AB straight almost from the #1 guide path and passes through a side wall 13 of a planar resonance circuit 10 and is not almost outputted to guide paths #2, #3. Thus, the circulator is used for 2-way communication of a light wave by using the fiber line.