US4585307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compound optical phase grating and switching devices comprising such a grating
Assignee: US Philips Corp
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Filing: 1984-01-27
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Granted: 1986-04-29
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Expires: 2004-01-27
Abstract
Abstract The invention relates to a compound blazed optical phase grating. The grating comprises at least two grating sections which are disposed opposite each other in parallel planes. The gratings have grooves which extend parallel to each other. The grating sections have equal grating periods and are movable relative to each other within their planes and perpendicular to the grooves. Over one grating period, the optical path length varies at least substantially parabolically and symmetrically relative to the grating period. The path length varies in such a manner that when both grating sections are symmetrically arranged relative to a common line perpendicular to the grating planes, the optical path length through the compound grating is uniform across the grating. Various optical switches and switching matrixes can be formed by using such compound phase gratings.
Inventors
- 👤 Hans Dammann
- 👤 Heinrich Kurz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:31
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/35; G02B6/354; G02B6/3544; G02B6/3546; G02B27/00; G02B27/42; G02B27/4272; G02B27/4277; G02B6/351
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
178 words
A compound optical phase grating comprising: a substantially planar first grating section having parallel grooves, having a grating period, and having a grating profile which is repeated once each grating period; and a substantially planar second grating section having parallel grooves, having a grating period equal to the grating period of the first grating section, and having a grating profile which is repeated once each grating period, said second grating section being arranged opposite and parallel to the first grating section with the grooves in the first grating section parallel to the grooves in the second grating section, the first and second grating sections being movable relative to each other in their planes in a direction perpendicular to the grooves; characterized in that: each grating profile is at least substantially parabolic; each grating profile is symmetrical about the center of each grating period; and when the first and second grating sections are both arranged symmetrically about a common line perpendicular to the grating, the compound grating has an optical path length therethrough which is uniform across the grating.
Claim 2
Dependent Claim
178 words
A compound optical phase grating comprising: a substantially planar first grating section having parallel grooves, having a grating period, and having a grating profile which is repeated once each grating period; and a substantially planar second grating section having parallel grooves, having a grating period equal to the grating period of the first grating section, and having a grating profile which is repeated once each grating period, said second grating section being arranged opposite and parallel to the first grating section with the grooves in the first grating section parallel to the grooves in the second grating section, the first and second grating sections being movable relative to each other in their planes in a direction perpendicular to the grooves; characterized in that: each grating profile is at least substantially parabolic; each grating profile is symmetrical about the center of each grating period; and when the first and second grating sections are both arranged symmetrically about a common line perpendicular to the grating, the compound grating has an optical path length therethrough which is uniform across the grating.
Claim 3
Dependent Claim
27 words
A compound optical phase grating as claimed in claim 1, characterized in that each grating section is a digital phase grating such that the grooves are steps.
Claim 4
Dependent Claim
20 words
A compound optical phase grating as claimed in claim 2, characterized in that each grating section is a refractive-index grating.
Claim 5
Dependent Claim
20 words
A compound optical phase grating as claimed in claim 2, characterized in that each grating section is a relief grating.
Claim 6
Dependent Claim
29 words
A compound optical phase grating as claimed in claim 4, characterized in that one grating section is provided with a reflective layer on a surface of the grating section.
Claim 7
Dependent Claim
55 words
A compound optical phase grating as claimed in claim 5, characterized in that: each grating section has an odd number of grating steps in each grating period; and the optical path length through the grating steps varies as a function of position over the grating period, the function being parabolic with a superimposed linear portion.
Claim 8
Dependent Claim
47 words
A compound optical phase grating as claimed in claim 5, characterized in that: each grating section has an even number of grating steps in each grating period; and the optical path length through the grating steps varies as a parabolic function of position over the grating period.
Claim 9
Dependent Claim
27 words
A compound optical phase grating as claimed in claim 5, further comprising a piezoelectric actuator for moving the first and second grating sections relative to each other.
Claim 10
Dependent Claim
21 words
A compound optical phase grating as claimed in claim 1, characterized in that each grating section is an anlaog phase grating.
Claim 11
Dependent Claim
225 words
A compound optical phase grating comprising: a substantially planar first grating section having parallel grooves, having a grating period, and having a grating profile which is repeated once each grating period; and a substantially planar second grating section having parallel grooves, having a grating period equal to the grating period of the first grating section, and having a grating profile which is repeated once each grating period, said second grating section being arranged opposite and parallel to the first grating section with the grooves in the first grating section parallel to the grooves in the second grating section, the first and second grating sections being movable relative to each other in their planes in a direction perpendicular to the grooves; characterized in that: each grating profile is at least substantially parabolic; each grating profile is symmetrical about the center of each grating period; the profile of the first grating section is a negative copy of the profile of the second grating section; when the first and second grating sections are both arranged symmetrically about a common line perpendicular to the grating, the compound grating has an optical path length therethrough which is uniform across the grating; and when the grating sections are moved relative to one another, the grating has an effective blaze which is changed to diffract incident light into a different diffraction order.
Claim 12
Dependent Claim
225 words
A compound optical phase grating comprising: a substantially planar first grating section having parallel grooves, having a grating period, and having a grating profile which is repeated once each grating period; and a substantially planar second grating section having parallel grooves, having a grating period equal to the grating period of the first grating section, and having a grating profile which is repeated once each grating period, said second grating section being arranged opposite and parallel to the first grating section with the grooves in the first grating section parallel to the grooves in the second grating section, the first and second grating sections being movable relative to each other in their planes in a direction perpendicular to the grooves; characterized in that: each grating profile is at least substantially parabolic; each grating profile is symmetrical about the center of each grating period; the profile of the first grating section is a negative copy of the profile of the second grating section; when the first and second grating sections are both arranged symmetrically about a common line perpendicular to the grating, the compound grating has an optical path length therethrough which is uniform across the grating; and when the grating sections are moved relative to one another, the grating has an effective blaze which is changed to diffract incident light into a different diffraction order.
Claim 13
Dependent Claim
21 words
A compound optical phase grating as claimed in claim 10, characterized in that each grating section is an analog phase grating.
Claim 14
Dependent Claim
27 words
A compound optical phase grating as claimed in claim 10, characterized in that each grating section is a digital phase grating such that the grooves are steps.
Claim 15
Dependent Claim
55 words
A compound optical phase grating as claimed in claim 12, characterized in that: each grating section has an odd number of grating steps in each grating period; and the optical path length through the grating steps varies as a function of position over the grating period, the function being parabolic with a superimposed linear portion.
Claim 16
Dependent Claim
47 words
A compound optical phase grating as claimed in claim 12, characterized in that: each grating section has an even number of grating steps in each grating period; and the optical path length through the grating steps varies as a parabolic function of position over the grating period.
Claim 17
Dependent Claim
199 words
A compound optical phase grating comprising: a substantially planar first grating section having parallel grooves, having a grating period, and having a grating profile which is repeated once each grating period; and a substantially planar second grating section having parallel grooves, having a grating period equal to the grating period of the first grating section, and having a grating profile which is repeated once each grating period, said second grating section being arranged opposite and parallel to the first grating section with the grooves in the first grating section parallel to the grooves in the second grating section, the first and second grating sections being movable relative to each other in their planes in a direction perpendicular to the grooves; characterized in that: each grating profile is at least substantially parabolic; each grating profile is symmetrical about the center of each grating period; when the first and second grating sections are both arranged symmetrically about a common line perpendicular to the grating, the compound grating has an optical path length therethrough which is uniform across the grating; and the first and second grating sections are moveable relative to one another over a distance not greater than the grating period.
Claim 18
Dependent Claim
199 words
A compound optical phase grating comprising: a substantially planar first grating section having parallel grooves, having a grating period, and having a grating profile which is repeated once each grating period; and a substantially planar second grating section having parallel grooves, having a grating period equal to the grating period of the first grating section, and having a grating profile which is repeated once each grating period, said second grating section being arranged opposite and parallel to the first grating section with the grooves in the first grating section parallel to the grooves in the second grating section, the first and second grating sections being movable relative to each other in their planes in a direction perpendicular to the grooves; characterized in that: each grating profile is at least substantially parabolic; each grating profile is symmetrical about the center of each grating period; when the first and second grating sections are both arranged symmetrically about a common line perpendicular to the grating, the compound grating has an optical path length therethrough which is uniform across the grating; and the first and second grating sections are moveable relative to one another over a distance not greater than the grating period.
References Cited (Backward Citations)
US4257673A
Cited
US4360251A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |