Patent ID: 6108120
Filing Date: 2000-08-22
Classification: G02F

Abstract:
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 said garnet single crystal in two or more of directions and varying a synthetic magnetic field synthesized from the external magnetic fields, wherein:said garnet single crystal has the (111) plane polished and the light beam is allowed to pass through said garnet single crystal along the <111> direction of said garnet single crystal perpendicular to the (111) plane; anda displacement path of a synthetic vector of the external magnetic fields is within a fan-shaped range of a stereographic projection chart of said garnet single crystal with the (111) plane taken as the center of said chart, said fan-shaped range being surrounded by two lines connecting a point indicating the (111) plane positioned at the center of said 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 said stereographic projection chart.