Patent US5467418A successfully refreshed from Google Patents.
US5467418A
Expired / Lapsed
US
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Frequency routing device having a spatially filtered optical grating for providing an increased passband width
Assignee: Avago Technologies International Sales Pte Ltd
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Filing: 1994-09-02
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Granted: 1995-11-14
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Expires: 2014-09-02
Abstract
Abstract An optical appliance includes at least one input waveguide and a first free space region connected to the input waveguide. A first plurality of waveguides is connected to the first free space region. An optical grating, which is connected to the first plurality of waveguides, includes a plurality of unequal length waveguides that are divided into at least three waveguide groups. Adjacent waveguides that belong to the same group have a substantially constant path length difference between them while adjacent waveguides belonging to different groups of waveguides have a path length difference between them that differs from the constant path length difference by an odd integer multiple of one-half a preselected wavelength. A second plurality of waveguides is connected to the optical grating and a second free space region is connected to he second plurality of waveguides. At least one output waveguide is connected to the second fee space region. As a result of this arrangement, this optical apparatus has a spectral efficiency which is maximized by providing a relatively wide passband and a relatively narrow channel spacing for a given crosstalk level.
Inventors
- 👤 Corrado Dragone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:28
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/12007; G02B6/12009; G02B6/12011
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
154 words
An optical apparatus comprising: at least one input waveguide; a first free space region connected to the at least one waveguide; a first plurality of waveguides connected to the first free space region; an optical grating connected to the first plurality of waveguides comprising a plurality of unequal length waveguides; a second plurality of waveguides connected to the optical grating; a second free space region connected to the second plurality of waveguides; and at least one output waveguide connected to the second free space region; and wherein said optical grating has a grating distribution representing a distribution of transmission coefficient contributions among the plurality of waveguides of the optical grating as determined at a wavelength of maximum transmission, said grating distribution having two intervals in which the transmission coefficient contributions have a predetermined phase that is opposite to the phase of the transmission coefficient contributions in a remaining portion of the optical grating distribution.
Claim 2
Dependent Claim
154 words
An optical apparatus comprising: at least one input waveguide; a first free space region connected to the at least one waveguide; a first plurality of waveguides connected to the first free space region; an optical grating connected to the first plurality of waveguides comprising a plurality of unequal length waveguides; a second plurality of waveguides connected to the optical grating; a second free space region connected to the second plurality of waveguides; and at least one output waveguide connected to the second free space region; and wherein said optical grating has a grating distribution representing a distribution of transmission coefficient contributions among the plurality of waveguides of the optical grating as determined at a wavelength of maximum transmission, said grating distribution having two intervals in which the transmission coefficient contributions have a predetermined phase that is opposite to the phase of the transmission coefficient contributions in a remaining portion of the optical grating distribution.
Claim 3
Dependent Claim
45 words
The optical apparatus of claim 1 wherein said two intervals each correspond to preselected ones of the unequal length waveguides of the optical grating, said preselected waveguides being substantially symmetrically disposed about a a centralmost group of the unequal length waveguides of the optical grating.
Claim 4
Dependent Claim
24 words
The optical apparatus of claim 2 wherein said two intervals and said remaining interval form a grating distribution that is a substantially continuous function.
Claim 5
Dependent Claim
20 words
The optical apparatus of claim 1 wherein said grating distribution produces a maximum crosstalk that is below a predetermined value.
Claim 6
Dependent Claim
150 words
An optical apparatus comprising: at least one input waveguide; a first free space region connected to the at least one waveguide; a first plurality of waveguides connected to the first free space region; an optical grating connected to the first plurality of waveguides comprising a plurality of unequal length waveguides that are divided into at least three groups of waveguides, wherein adjacent waveguides belonging to a common one of said groups have a substantially constant path length difference therebetween, and adjacent waveguides belonging to different ones of said groups of waveguides have a path length difference therebetween that differs from said constant path length difference by an odd integer multiple of one-half a preselected wavelength; a second plurality of waveguides connected to the optical grating; a second free space region connected to the second plurality of waveguides; and at least one output waveguide connected to the second free space region.
Claim 7
Dependent Claim
150 words
An optical apparatus comprising: at least one input waveguide; a first free space region connected to the at least one waveguide; a first plurality of waveguides connected to the first free space region; an optical grating connected to the first plurality of waveguides comprising a plurality of unequal length waveguides that are divided into at least three groups of waveguides, wherein adjacent waveguides belonging to a common one of said groups have a substantially constant path length difference therebetween, and adjacent waveguides belonging to different ones of said groups of waveguides have a path length difference therebetween that differs from said constant path length difference by an odd integer multiple of one-half a preselected wavelength; a second plurality of waveguides connected to the optical grating; a second free space region connected to the second plurality of waveguides; and at least one output waveguide connected to the second free space region.
Claim 8
Dependent Claim
15 words
The apparatus of claim 5 wherein said preselected wavelength is a wavelength of maximum transmission.
Claim 9
Dependent Claim
28 words
The apparatus of claim 5 wherein preselected waveguides in said three groups of waveguides have a predetermined amount of optical loss for producing a predetermined level of crosstalk.
Claim 10
Dependent Claim
33 words
The apparatus of claim 7 wherein said preselected waveguides each include two waveguide segments laterally displaced with respect to one another by a predetermined amount for providing the predetermined amount of optical loss.
Claim 11
Dependent Claim
45 words
The apparatus of claim 5 wherein selected ones of the unequal length waveguides of the optical grating each include two waveguide segments laterally displaced with respect to one another by a preselected amount for providing sufficient optical loss to achieve a predetermined level of cross-talk.
Claim 12
Dependent Claim
34 words
The apparatus of claim 9 wherein the predetermined amount of optical loss provides a distribution of transmission coefficient contributions among said unequal length waveguides of the optical grating that is a substantially continuous function.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-11-13 | 1999-05-15 | 1999-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-13 | 2003-05-15 | 2003-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-13 | 2007-05-15 | 2007-11-14 | $7700.00 | Window Closed / Lapsed |