Patent US5745618A successfully refreshed from Google Patents.
US5745618A
Expired / Lapsed
US
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Optical device having low insertion loss
Assignee: Nokia of America Corp
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Filing: 1997-02-04
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Granted: 1998-04-28
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Expires: 2017-02-04
Abstract
Abstract An optical device 201, having one or more input waveguides 25 coupled to one side of a slab waveguide 20 and an array of output waveguides 26 coupled to an other side of the slab waveguide, is improved by including a transition region 22 immediately adjacent to the slab that operates to reduce insertion loss between the waveguide array 26 and the slab waveguide. The transition region includes a number of silica paths (a I . . . a n ) that intersect the waveguide array. The silica paths have widths W(a n ) that progressively decrease as they become further away from the slab waveguide. The silica paths are parallel to each other and perpendicular to the waveguide array. Disclosed embodiments include an M×N star coupler, a Dense Waveguide Division Multiplexer, and a 1×N power splitter. In each of these embodiments, insertion loss is substantially reduced over similar devices not employing such a transition region.
Inventors
- 👤 Yuan P. Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:34
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/12007; G02B6/12009; G02B6/12011; G02B6/122; G02B6/125; G02B2006/12133; G02B2006/1215; G02B2006/12154
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
77 words
An optical device having at least one input waveguide coupled to one side of a slab waveguide and an array of output waveguides coupled to an other side of the slab waveguide, CHARACTERIZED BY a transition region, which is immediately adjacent to the slab waveguide and which comprises a plurality (n) of silica paths that intersect the output waveguide array, the silica paths having widths that progressively decrease as they become further away from the slab waveguide.
Claim 2
Dependent Claim
77 words
An optical device having at least one input waveguide coupled to one side of a slab waveguide and an array of output waveguides coupled to an other side of the slab waveguide, CHARACTERIZED BY a transition region, which is immediately adjacent to the slab waveguide and which comprises a plurality (n) of silica paths that intersect the output waveguide array, the silica paths having widths that progressively decrease as they become further away from the slab waveguide.
Claim 3
Dependent Claim
36 words
The optical device of claim 1 wherein the slab waveguide and the output waveguide array each comprise a light-carrying (core) material whose index of refraction is equal to the index of refraction of the silica paths.
Claim 4
Dependent Claim
41 words
The optical device of claim 2 wherein the separation between each pair of silica paths has a lower index of refraction than the silica paths, the widths of the separation gaps increasing as they become further away from the slab waveguide.
Claim 5
Dependent Claim
15 words
The optical device of claim 2 wherein the silica paths are parallel to each other.
Claim 6
Dependent Claim
17 words
The optical device of claim 2 wherein the silica paths are perpendicular to the output waveguide array.
Claim 7
Dependent Claim
24 words
The optical device of claim 1 wherein the width of each silica path decreases linearly as it becomes further away from the slab waveguide.
Claim 8
Dependent Claim
8 words
The optical device of claim 1 wherein: n>10.
Claim 9
Dependent Claim
26 words
The optical device of claim 1 wherein the optical device comprises a star coupler having a plurality of input waveguides and a plurality of output waveguides.
Claim 10
Dependent Claim
26 words
The optical device of claim 1 wherein the optical device comprises a branch power splitter having a single input waveguide and a plurality of output waveguides.
Claim 11
Dependent Claim
67 words
An optical device comprising a slab waveguide coupled to a waveguide array along a side thereof, the device further comprising a plurality (n) of silica paths, which are immediately adjacent to the side of the slab and which intersect the waveguide array, each of the silica paths (a n ) having a width W(a n ) that decreases as it becomes further away from the slab waveguide.
Claim 12
Dependent Claim
67 words
An optical device comprising a slab waveguide coupled to a waveguide array along a side thereof, the device further comprising a plurality (n) of silica paths, which are immediately adjacent to the side of the slab and which intersect the waveguide array, each of the silica paths (a n ) having a width W(a n ) that decreases as it becomes further away from the slab waveguide.
Claim 13
Dependent Claim
21 words
The optical device of claim 10 wherein W(a n ) decreases linearly as it becomes further away from the slab waveguide.
Claim 14
Dependent Claim
49 words
The optical device of claim 10 wherein a separation gap (s n ), having a width W(s n ), is positioned between each pair of silica paths, the combined width of each silica path and its adjacent separation gap having the following relationship: W(a.sub.n)+W(s.sub.n)=Λ, where Λ is a constant.
Claim 15
Dependent Claim
12 words
The optical device of claim 12 wherein Λ is about 20 μm.
Claim 16
Dependent Claim
8 words
The optical device of claim 12 wherein: n>10.
Claim 17
Dependent Claim
9 words
The optical device of claim 14 wherein: 20 <n<40.
Claim 18
Dependent Claim
93 words
An optical device comprising a first star coupler having a first waveguide array that is coupled to a first slab waveguide; a second star coupler having a second waveguide array that is coupled to a second slab waveguide, which includes a transition region comprising a number of silica paths immediately adjacent thereto that intersect the second waveguide array, the silica paths having widths that progressively decrease as they become further away from the second slab waveguide; and a grating comprising a plurality of unequal-length waveguides that interconnect the first and second waveguide arrays.
Claim 19
Dependent Claim
93 words
An optical device comprising a first star coupler having a first waveguide array that is coupled to a first slab waveguide; a second star coupler having a second waveguide array that is coupled to a second slab waveguide, which includes a transition region comprising a number of silica paths immediately adjacent thereto that intersect the second waveguide array, the silica paths having widths that progressively decrease as they become further away from the second slab waveguide; and a grating comprising a plurality of unequal-length waveguides that interconnect the first and second waveguide arrays.
Claim 20
Dependent Claim
45 words
The optical device of claim 16 wherein the first slab waveguide includes a transition region comprising a plurality of silica paths that intersect the first waveguide array, the silica paths having widths that progressively decrease as they become further away from the first slab waveguide.
Claim 21
Dependent Claim
25 words
The optical device of claim 16 wherein the width of each silica path decreases linearly as it becomes further away from the second slab waveguide.
Claim 22
Dependent Claim
16 words
The optical device of claim 16 wherein the number of silica paths is greater than ten.
Claim 23
Dependent Claim
24 words
The optical device of claim 16 wherein the silica paths are substantially parallel to each other and substantially perpendicular to the second waveguide array.
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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) | 2001-04-27 | 2001-10-27 | 2002-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-27 | 2005-10-27 | 2006-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-27 | 2009-10-27 | 2010-04-28 | $7700.00 | Window Closed / Lapsed |