Retroreflector detectors
First Claim
Patent Images
1. An optics arrangement, comprising:
- a polarized beam splitter arranged along an collection axis;
a first quarter waveplate arranged along the collection axis;
a second quarter waveplate arranged along the collection axis, wherein the second quarter waveplate is optically coupled to the first quarter waveplate by the polarized beam splitter to limit return of polarized illumination originating in a scene being illuminated for retroreflector detection; and
a collector arranged along the collection axis, wherein the second quarter waveplate is arranged between the collector and the polarized beam splitter along the collection axis.
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Abstract
An optics arrangement includes a polarized beam splitter arranged along an collection axis, a first quarter waveplate arranged along the collection axis, and a second quarter waveplate. The second quarter waveplate is arranged along the collection axis and is optically coupled to the first quarter waveplate by the polarized beam splitter to limit return of polarized illumination originating in a scene being illuminated for retroreflector detection. Retroreflector detectors and methods of imaging a scene are also described.
7 Citations
17 Claims
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1. An optics arrangement, comprising:
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a polarized beam splitter arranged along an collection axis; a first quarter waveplate arranged along the collection axis; a second quarter waveplate arranged along the collection axis, wherein the second quarter waveplate is optically coupled to the first quarter waveplate by the polarized beam splitter to limit return of polarized illumination originating in a scene being illuminated for retroreflector detection; and a collector arranged along the collection axis, wherein the second quarter waveplate is arranged between the collector and the polarized beam splitter along the collection axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A retroreflector detector, comprising:
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an optics arrangement including; a polarized beam splitter arranged along an collection axis; a first quarter waveplate arranged along the collection axis; a second quarter waveplate arranged along the collection axis, wherein the second quarter waveplate is optically coupled to the first quarter waveplate by the polarized beam splitter to limit return of polarized illumination originating in a scene being illuminated for retroreflector detection; an illuminator arranged along a source axis, wherein the source axis intersects the collection axis within the polarized beam splitter; and a collector comprising a photodiode array arranged along the collection axis, wherein the second quarter waveplate is arranged between the collector and the polarized beam splitter. - View Dependent Claims (13, 14)
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15. An imaging method, comprising:
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receiving polarized illumination; transmitting the polarized illumination along a collection axis through first and second quarter waveplates optically coupled by a polarized beam splitter, wherein the polarized illumination is received at the first quarter waveplate prior to being transmitted by the polarized beam splitter; flipping polarization of the polarization of the received illumination during transmission through one of the first and second quarter waveplates; and receiving broadband illumination through the first quarter waveplate at the polarized beam splitter, and attenuating the broadband illumination with the polarized beam splitter. - View Dependent Claims (16)
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17. An imaging method, comprising:
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receiving polarized illumination; transmitting the polarized illumination along a collection axis through first and second quarter waveplates optically coupled by a polarized beam splitter; flipping polarization of the polarization of the received illumination during transmission through one of the first and second quarter waveplates, wherein the polarized illumination is received at the first quarter waveplate prior to being transmitted by the polarized beam splitter; and reflecting polarized illumination at an angle oblique relative to the collection axis.
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Specification