Devices for depolarizing polarized light
OwnerXiaotian Steve Yaoinventor
Life of this patent
Estimating the term…
Abstract
Depolarizing system for polarized light formed of a birefringence crystal wedge which receives the beam of polarized light at a first surface and outputs spatially depolarized light from its output surface. The wedge may include small steps on one of the surfaces or special orientations to depolarize the light. The wedge may be substantially triangular in shape so that the surface decreases from one side to the other.
Claims52
A system to depolarize a beam of polarized light comprising:
- a first birefringent crystal wedge to receive the beam of polarized light at an input first surface, the first birefringent crystal wedge to output spatially depolarized light from an output surface, wherein one of the input and output surfaces of the birefringent crystal wedge includes a plurality of small steps, each step including a subsurface parallel to the other of the input and output surfaces.
A system to depolarize a beam of polarized light comprising:
- an array of birefringent crystal chips arranged to from a plane, each crystal chips having an optic axis oriented such that a substantial component of the optic axis is oriented perpendicular to the propagation direction of the beam of light being depolarized, each chip dimensioned to be substantially smaller than a cross section of the beam of polarized light.
A system to depolarize light from a fiber comprising:
- a collimating lens to collimate light from a first fiber;
- a depolarizing element having a spatially-varying phase difference along the two orthogonal axes on each light ray across a beam of the collimated light to produce a difference of about 2π between a first phase difference along the two orthogonal axes of one light ray on one side of the beam and a second phase difference along the two orthogonal axes of another light ray on an opposing side of the beam at the output optical surface to spatially depolarize the collimated light output by the collimating lens;
- and
- a focusing lens to focus the depolarized output by the depolarizing element into a second fiber segment.
A device, comprising:
- a birefringent element having an input optical surface and an output optical surface opposing said input optical surface and configured to have different refractive indices along two mutually orthogonal axes that are substantially parallel to said input optical surface,
- wherein said input and output optical surfaces form an angle with respect to each other to produce different phase delays for different spatial parts of a collimated input optical beam received at said input optical surface to depolarize the collimated input beam, and
- wherein a tangent of said angle is equal to or greater than λ/(Δn·D), where λ is a wavelength of the input optical beam, Δn is a difference between said different refractive indices, and D is a cross-sectional dimension of the input optical beam.
A device, comprising:
- a first birefringent element having a first input optical surface and a first output optical surface opposing said first input optical surface with a first angle, and configured to have a first optic axis that is substantially parallel to said first input optical surface, and
- a second birefringent element having a second input optical surface facing said first output optical surface and a second output optical surface opposing said second input optical surface with a second angle, and configured to a second optic axis that is substantially parallel to said second output optical surface and perpendicular to said first optic axis,
- wherein said first and said second angles are selected to produce a difference of about πn between phase differences along said two orthogonal axes of two light rays respectively located on two opposite sides of an input beam at said second output optical surface.
A device, comprising:
- a birefringent element having an input side configured to have an input optical surface and an output side opposing said input side, said output side configured to have a plurality of output optical surfaces substantially parallel to said input optical surface and having different distances from said input optical surface,
- wherein said birefringent element is configured to have an optic axis substantially parallel to said input optical surface to produce different polarizations on different portions of an input beam by different output optical surfaces.
A device for depolarizing an optical beam, comprising a plurality of birefringent elements arranged to form a plane substantially perpendicular to a direction of an optical beam, each birefringent element having an optic axis with an in-plane component projected in said plane, and orientations of in-plane components of optic axes of said plurality of birefringent elements being either randomly distributed or substantially evenly distributed between 0 degree and 180 degree, wherein each birefringent element is sized to be substantially smaller than a cross section of the optical beam to allow for different birefringent elements in a path of the optical beam to cause different output polarizations in different parts of the cross section of the optical beam.
A device, comprising:
- a birefringent element having a first side configured to have a first optical surface and a second side facing away said first side, said second side configured to have a plurality of small optical surfaces substantially parallel to said first optical surface and having different distances from said first optical surface,
- wherein said birefringent element is configured to have an optic axis substantially parallel to said first optical surface to produce different polarizations on different portions of an optical beam that transmits said birefringent element through said first and said second sides with a cross section covering at least a portion of said plurality of small optical surfaces.
Dependencies are inferred from the claim text.