US5467418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency routing device having a spatially filtered optical grating for providing an increased passband width
Assignee: Avago Technologies International Sales Pte Ltd
•
Filing: 1994-09-02
•
Granted: 1995-11-14
•
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 16:18
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.
References Cited (Backward Citations)
US4243297A
Cited
US4482994A
Cited
US4566753A
Cited
US4707062A
Cited
US4650279A
Cited
US4750802A
Cited
US4786131A
Cited
US4904042A
Cited
US5039993A
Cited
US5002350A
Cited
US5136671A
Cited
US5243672A
Cited
US5339157A
Cited
US5367586A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 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 |