Adjustable optical attenuator
AssigneeJDS Fitel Inc.
InventorsJohn O. Smiley, Robert Laflamme
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Abstract
An optical attenuator for attenuating a collimated beam of light propagating along an optical path while preserving the composition of polarization of the collimated beam of light is disclosed. The optical attenuator comprises a beam attenuator for attenuating a portion of the collimated beam of light when a portion of the beam attenuator is disposed within the optical path. The beam attenuator has a cross section along a plane perpendicular to the direction of propagation of the collimated beam of light of the portion of the attenuator in the shape of a wedge. The attenuation is varied using a controller for moving the beam attenuator in order to vary a size of the portion of the wedge within the optical path.
Claims20
A method of attenuating a beam of light having a circular cross-section comprising the step of disposing a member having a substantially opaque beam attenuating portion within the beam of light, the intersection of the beam attenuating portion of the member and the beam of light defining a beam region that is smaller than the beam of the light and having two substantially equal sides defining an angle therebetween of other than 0 degrees and 180 degrees, the two sides having a central line of symmetry coincident with a line of symmetry through the centre of the circle, the angle moving along the line of symmetry.
An optical attenuator for attenuating a beam of light having a circular cross-section, the optical attenuator comprising:
- a beam attenuator which is at least partially light blocking for attenuating a portion of the beam of light when a portion of the beam attenuator is disposed within the beam of light, the beam attenuator being disposed within the beam of light such that the intersection of the beam attenuator and the beam of light defining a beam region that is smaller than the beam of the light and having two substantially equal sides having an angle other than 0 degrees and 180 degrees therebetween, the two sides having a central line of symmetry coincident with a line of symmetry through the centre of the circle, the angle moving along the line of symmetry;
- and,
- a controller for moving the beam attenuator in order to vary a size of the portion of the beam attenuator within the beam of light.
Dependencies are inferred from the claim text.