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US 5,048,937 AGranted
Faraday rotator device and optical switch containing same
AssigneeHitachi Metals, Ltd.
InventorsShigeru Takeda, Satoshi Makio
Life of this patent
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AssigneeHitachi Metals, Ltd.
InventorsShigeru Takeda, Satoshi Makio
Estimating the term…
A Faraday rotator device containing (a) a Faraday rotator, (b) a wire winding encircling the Faraday rotator for changing the magnetization state of the Faraday rotator, and (c) a hollow yoke surrounding the Faraday rotator and the wire winding for forming a substantially closed magnetic circuit together with the Faraday rotator, the hollow yoke having an opening in each of front and rear walls in alignment with the Faraday rotator for permitting a light to pass through the hollow yoke and the Faraday rotator. The optical switch containing a pair of polarizers disposed on front and rear sides of the Faraday rotator device, the magnetization direction of the Faraday rotator being reversible to change the optical path. The hollow yoke is made of a soft magnetic material or a semi-hard magnetic material.
A Faraday rotator device comprising:
An optical switch comprising a Faraday rotator device having (a) a Faraday rotator, (b) a wire winding encircling said Faraday rotator for changing the magnetization state of said Faraday rotator, (c) a hollow yoke having a body portion having an inner diameter larger than an outer diameter of said Faraday rotator and front and rear walls each having an opening of a smaller diameter than the outer diameter of said Faraday rotator, said yoke surrounding said Faraday rotator and said wire winding for forming a substantially closed magnetic circuit together with said Faraday rotator, said openings of said hollow yoke being in alignment with said Faraday rotator for permitting a light beam to pass through said hollow yoke and said Faraday rotator;
Dependencies are inferred from the claim text.