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US 7,065,284 B2Granted
Variable optical attenuator
AssigneeHitachi Metals, Ltd.
InventorsMasahiro Ao, Shinji Furuichi
Life of this patent
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Abstract
The invention provides a variable optical attenuator capable of adjusting the attenuation of an optical signal to obtain the optical signal having a controlled intensity. The variable optical attenuator includes a circular loop formed by winding an optical fiber by at least one turn. The circular loop of the optical fiber is mechanically transformed into an oval loop to change the curvature radius at the deflected part of the optical fiber so that the attenuation of the output light is adjusted.
Claims2
A variable optical attenuator comprising:
- a circular loop formed by winding by at least one turn an optical fiber having an input end and an output end;
- and
- an actuator which, at two points positioned on the circular loop and corresponding to each end of a diametrical line of the circular loop, applies force in an opposite direction with respect to the two points along the diametrical line to transform the circular loop into an oval loop so that an amount of output light of the optical fiber is attenuated relative to an amount of input light of the optical fiber,
- wherein a minimum curvature radius of an oval loop formed by transforming the circular loop is 10 to 35 mm.
1 more element
Dependencies are inferred from the claim text.