Fdk Corporation

Youichi Suzuki

Hirotaka Kawai

Hiromitsu Umezawa

Hidenori Nakada

A Faraday rotation angle varying apparatus for controlling a Faraday rotation angle of a light beam passing through a garnet single crystal having a Faraday effect by applying external magnetic fields to the garnet single crystal in two or more of directions and varying a synthetic magnetic field synthesized from the external magnetic fields is disclosed. According to an aspect of the present invention, the garnet single crystal has the (111) plane polished and the light beam is allowed to pass through the garnet single crystal along the &lt;111&gt; direction of the garnet single crystal perpendicular to the (111) plane. A displacement path of a synthetic vector of the external magnetic fields is within a fan-shaped range (peripheral lines of the fan-shape inclusive) of a stereographic projection chart of the garnet single crystal with the (111) plane taken as the center of the chart. The fan-shaped range is surrounded by two lines connecting a point indicating the (111) plane positioned at the center of the stereographic projection chart to two positions apart 10.degree. rightward and leftward from a point indicating one of crystal planes equivalent to the (110) plane positioned on the outermost peripheral circle of the stereographic projection chart.

Growing community of inventors

Shizuoka, Japan

Youichi Suzuki