Flexible rejection filter (U)
AssigneeRockwell International Corporation
InventorsMohsen Khoshnevisan, Pochi A. Yeh, Mark D. Ewbank
Life of this patent
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Abstract
A flexible rejection filter removes coherent radiation from an incoming beam of light. The filter includes a beamsplitter for dividing the transmitted portion into first and second beams. A photorefractive crystal in the paths of the first and second beams couples coherent radiation from the first beam to the second beam. A focal plane detector follows the crystal in the path of the first beam for sensing the incoherent radiation in the first beam, while a beam dump follows the crystal in the path of the second beam for absorbing the coherent radiation of the second beam. Other filter configurations can utilize contradirectional energy coupling or resonator structures in conjunction with photorefractive media.
Claims22
A flexible rejection filter for removing coherent radiation from an incoming beam of light, comprising:
- a beamsplitter for dividing the incoming beam into first and second beams;
- and
- a photorefractive crystal in the paths of the first and second beams, and oriented with respect to the paths of the first and second beams in the crystal to optimize the formation of a phase hologram in the crystal, for coupling coherent radiation from the first beam to the second beam.
A flexible rejection filter for removing coherent radiation from an incoming beam of light, comprising:
- a beamsplitter for dividing the incoming beam into first and second beams;
- and
- a photorefractive crystal in the paths of the incoming beam and the second beam, and oriented with respect to the paths of the incoming and second beams in the crystal to optimize the formation of a phase hologram in the crystal, for coupling coherent radiation from the incoming beam to the second beam.
A flexible rejection filter for removing coherent radiation from an incoming beam of light, comprising:
- a polarizer for transmitting only that portion of the incoming beam having a first polarization direction;
- a beamsplitter for dividing the transmitted portion into first and second beams;
- a photorefractive crystal in the paths of the first and second beams, and oriented with respect to the paths of the first and second beams in the crystal to optimize the formation of a phase hologram in the crystal, for coupling coherent radiation from the first beam to the second beam;
- a focal plane detector following the crystal in the path of the first beam for sensing the incoherent radiation in the first beam;
- and
- a beam dump following the crystal in the path of the second beam for absorbing the second beam.
A flexible rejection filter for removing coherent radiation from an incoming beam of light, comprising:
- a polarizer for transmitting only that portion of the incoming beam having a first polarization direction;
- a partially reflecting mirror for dividing the transmitted portion into a transmitted first beam and a reflected beam;
- a photorefractive crystal in the paths of the first and second beams, and oriented with respect to the paths of the first and second beams in the crystal to optimize the formation of a phase hologram in the crystal, for coupling coherent radiation from the first beam to the second beam;
- a fully reflecting mirror between the partially reflecting mirror and the crystal in the path of the first beam for making the optical path of the first beam equal to the optical path of the second beam between the beamsplitter and the crystal;
- a focal plane detector following the crystal in the path of the first beam for sensing the incoherent radiation in the first beam;
- and
- a beam dump following the crystal in the path of the second beam for absorbing the second beam.
A method for removing coherent radiation from an incoming beam of light, comprising the steps of:
- dividing the incoming beam into first and second beams;
- and
- placing a photorefractive crystal in the paths of the first and second beams, and oriented with respect to the paths of the first and second beams in the crystal to optimize the formation of a phase hologram in the crystal, to couple coherent radiation from the first beam to the second beam.
Dependencies are inferred from the claim text.