US5757547A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High efficiency homogeneous polarization converter
Assignee: Polycom LLC
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Filing: 1995-04-24
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Granted: 1998-05-26
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Expires: 2015-04-24
Abstract
Abstract A polarization converter for polarizing a light beam by converting all light waves to the same orientation comprises 1) a first beam dividing matrix of refractory material for dividing a single, large light beam into smaller sub-beam 2) a second beam focusing matrix for polarizing select portions of the sub-beams, and 3) a series of narrow and shallow polarizing cells. The second beam focusing matrix further comprises a plurality of concave lenses for redirecting each sub-beam and quarter wave retarders disposed in alignment with, and adjacent to, the reflective side of an equal plurality of mirror segments. The polarizing cells include either a first beamsplitter or a second beamsplitter, where the first beamsplitters and second beamsplitters are disposed in opposing diagonal fashion and in an alternating manner. Lightwaves of a selected polarization pass directly through the first beamsplitter and out of the polarizing cell, while all other lightwaves are horizontally reflected by the first beamsplitter and directed onto the second beamsplitter where they are redirected toward the quarter wave retarder. The reflected light passes through the quarter wave retarder, reflects off of the mirror and again passes through the quarter wave retarder. The wavelength of the light is retarded ninety degrees as a result of the two passes through the quarter-wave retarder, thus re-orienting the light to the selected orientation. The re-oriented p-waves pass through the second beamsplitter and exit the polarizing cell, join the original p-waves exiting the polarizing cells, and form a beam of polarized light.
Inventors
- 👤 Jeffrey C. Rodman
- 👤 Brian L. Hinman
- 👤 Pasquale Romano
- 👤 Arlie R. Conner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:42
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/30; G02B5/3025; G02B27/00; G02B27/28; G02B27/283; G02B27/285; G02B5/3083; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528; G02F1/133536; G02F1/13355; G02F1/1336; G02F1/13362
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
167 words
A polarization converter providing efficient conversion of non-polarized light to polarized light, comprising: a beam dividing matrix for dividing the non-polarized light into a plurality of sub-beams; a beam focusing matrix for focusing the sub-beams received from the beam dividing matrix; an array of polarizing cells for separating each sub-beam of non-polarized light into first and second light components having planes of polarization orthogonal to each other, each polarizing cell including: a first cell having a first beamsplitter positioned diagonally therewithin for reflecting the first light component and passing the second light component; and a second cell disposed adjacent the first cell, the second cell having a second beamsplitter positioned diagonally opposite the first beamsplitter for reflecting the first light component a second time; and means for rotating the plane of polarization of the first light component to be coincident with the plane of polarization of the second light component, the rotated first light component passing through the second beamsplitter and combining with the second light component.
Claim 2
Dependent Claim
167 words
A polarization converter providing efficient conversion of non-polarized light to polarized light, comprising: a beam dividing matrix for dividing the non-polarized light into a plurality of sub-beams; a beam focusing matrix for focusing the sub-beams received from the beam dividing matrix; an array of polarizing cells for separating each sub-beam of non-polarized light into first and second light components having planes of polarization orthogonal to each other, each polarizing cell including: a first cell having a first beamsplitter positioned diagonally therewithin for reflecting the first light component and passing the second light component; and a second cell disposed adjacent the first cell, the second cell having a second beamsplitter positioned diagonally opposite the first beamsplitter for reflecting the first light component a second time; and means for rotating the plane of polarization of the first light component to be coincident with the plane of polarization of the second light component, the rotated first light component passing through the second beamsplitter and combining with the second light component.
Claim 3
Dependent Claim
19 words
The polarization converter according to claim 1, wherein the beam focusing matrix comprises a plurality of concave directing lenses.
Claim 4
Dependent Claim
26 words
The polarization converter according to claim 2, wherein the means for rotating the polarization are disposed in alternating arrangement with the plurality of concave directing lenses.
Claim 5
Dependent Claim
23 words
The polarization converter according to claim 2, wherein the means for rotating the polarization and the plurality of concave directing lenses are co-planar.
Claim 6
Dependent Claim
44 words
The polarization converter according to claim 2, wherein the plurality of concave directing lenses are recessed with respect to the means for rotating the polarization, and further comprising walls disposed between the plurality of concave directing lenses and the means for rotating the polarization.
Claim 7
Dependent Claim
19 words
The polarization converter according to claim 1, wherein the beam dividing matrix comprises a plurality of convex dividing lenses.
Claim 8
Independent Claim
149 words
A method of efficiently converting non-polarized light into polarized light comprising the steps of: dividing the non-polarized light into a plurality of sub-beams; and for each of the plurality of sub-beams: directing the sub-beam into a first cell; separating the sub-beam into first and second light components having mutually orthogonal planes of polarization; directing the first light component from the first cell to a second cell disposed adjacent and diagonally opposite the first cell; directing the second light component from the first cell; directing the first light component from the second cell; rotating the plane of polarization of the first light component to be coincident with the plane of polarization of the second light component by twice passing the first light component through a quarter wave retarder; directing the rotated first light component through the second cell; and combining the rotated first light component with the second light component.
Claim 9
Independent Claim
149 words
A method of efficiently converting non-polarized light into polarized light comprising the steps of: dividing the non-polarized light into a plurality of sub-beams; and for each of the plurality of sub-beams: directing the sub-beam into a first cell; separating the sub-beam into first and second light components having mutually orthogonal planes of polarization; directing the first light component from the first cell to a second cell disposed adjacent and diagonally opposite the first cell; directing the second light component from the first cell; directing the first light component from the second cell; rotating the plane of polarization of the first light component to be coincident with the plane of polarization of the second light component by twice passing the first light component through a quarter wave retarder; directing the rotated first light component through the second cell; and combining the rotated first light component with the second light component.
Claim 10
Dependent Claim
30 words
The method according to claim 7, further comprising the step of: for each of the sub-beams, collimating the combined first and second light components to provide a polarized output beam.
Claim 11
Dependent Claim
24 words
The method according to claim 7, wherein the step of separating the sub-beam includes the step of directing the sub-beam to a first beamsplitter.
Claim 12
Dependent Claim
32 words
The method according to claim 7, wherein the step of directing the first light component from the second cell includes the step of directing the first light component from a second beamsplitter.
Claim 13
Dependent Claim
39 words
The method of claim 7, wherein the first light component is caused to pass through the quarter wave retarder a first time, to be reflected from a mirror, and to pass through the quarter wave retarder a second time.
Claim 14
Dependent Claim
38 words
The method of claim 7, wherein the step of directing the first light component includes the step of directing the rotated first light component includes the step of directing the rotated first light component through the second beamsplitter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-25 | 2001-11-24 | 2002-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-25 | 2005-11-24 | 2006-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-25 | 2009-11-24 | 2010-05-26 | $7700.00 | Window Closed / Lapsed |