Fizeau interferometer
First Claim
1. In combination:
- means for producing a beam of energy along a predetermined path;
means, disposed in the predetermined path, for transmitting a first portion of the produced beam to a target and reflecting a second portion of the produced beam; and
means, including the transmitting and reflecting means, for directing a target-reflected portion of the transmitted first beam portion and the reflected second beam portion to a detector along a common path, said directing means comprising means, disposed in the common path, for attenuating the reflected second beam portion along the common path and for coupling the target-reflected portion of the transmitted first beam portion along the common path with substantially no attenuation.
1 Assignment
0 Petitions
Accused Products
Abstract
An interferometer wherein detected local oscillator beam power is variable without varying detected target-reflected return beam power. A P-polarized beam of energy is produced along a predetermined path. First and second waveplates are serially disposed in the predetermined path. Also included are a beamsplitter disposed in the path between the first and second waveplates, and a polarization analyzer disposed in the path between the beam producing means and the first waveplate. A first portion of the P-polarized beam couples through the first waveplate, the beamsplitter and the second waveplate, and is transmitted to a target, the first and second waveplates altering the polarization of the transmitted beam to circular polarization. A circularly polarized portion of the transmitted beam reflected by the target couples through the second waveplate, the beamsplitter and the first waveplate and is incident on the polarization analyzer, the first and second waveplates altering the polarization of such beam to substantially entirely S-polarization. A second portion of the P-polarized beam couples through the first waveplate, reflects from the beamsplitter, recouples through the first waveplate and is incident on the polarization analyzer, the first waveplate changing the polarization of such beam to both P- and S-polarization components. The polarization analyzer directs to a detector for heterodyning substantially only the S-polarization component of the second beam portion and the S-polarization component of the substantially entirely S-polarized target reflected beam.
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Citations
15 Claims
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1. In combination:
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means for producing a beam of energy along a predetermined path; means, disposed in the predetermined path, for transmitting a first portion of the produced beam to a target and reflecting a second portion of the produced beam; and means, including the transmitting and reflecting means, for directing a target-reflected portion of the transmitted first beam portion and the reflected second beam portion to a detector along a common path, said directing means comprising means, disposed in the common path, for attenuating the reflected second beam portion along the common path and for coupling the target-reflected portion of the transmitted first beam portion along the common path with substantially no attenuation. - View Dependent Claims (2)
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3. In an apparatus wherein a first portion of a beam of energy is transmitted along a first path to a target and a second portion of the beam is reflected to a detector along a common path with a target-reflected portion of the transmitted first beam portion returned to the apparatus, said apparatus comprising:
means, disposed in the common path, for attenuating the reflected second beam portion along the common path while coupling substantially all of the target-reflected return beam portion along the common path. - View Dependent Claims (4)
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5. In combination:
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means for producing a beam of energy along a predetermined path; first and second waveplates serially disposed with the beam producing means in the predetermined path; a beamsplitter disposed in the predetermined path between the first and second waveplates; and a polarization analyzer disposed in the predetermined path between the beam producing means and the first waveplate. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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12. A method of transmitting a circularly polarized beam of energy to a target comprising the steps of:
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producing a P-polarized beam of energy and directing such beam along a predetermined path; changing the polarization of the beam a first predetermined amount to produce an elliptically polarized intermediate beam having S- and P-polarization components; coupling a portion of the elliptically polarized intermediate beam to a detector; changing the polarized of the intermediate beam a second predetermined amount to produce a circularly polarized beam; and transmitting the circularly polarized beam to the target. - View Dependent Claims (13, 14, 15)
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Specification