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Patent US5563970A successfully refreshed from Google Patents.
US5563970A
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Taper shapes for ultralow sidelobe levels in directional coupler filters
Assignee: RPX Clearinghouse LLC
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Filing: 1995-02-08
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Granted: 1996-10-08
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Expires: 2015-02-08
Abstract
Abstract An optical directional coupler filter having at least two guides; an input guide and a coupled guide. The spacing between the guides and hence the interactive strength is tailored so as to provide ultralow sidelobe levels at a narrow spectral bandwidth. A formula has been derived with respect to the tapered shape function of the waveguides in order to arrive at the optimum results.
Inventors
- 👤 Brent Little
- 👤 Chi Wu
- 👤 Wei-Ping Huang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:18
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/29; G02F1/31; G02F1/313; G02F1/3132; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/293; G02B6/29331; G02B6/29332; G02B6/29334
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
111 words
A directional coupler filter comprising: a first waveguide for receiving an optical signal having at least one predetermined wavelength; and a second waveguide in a spaced relationship to said first waveguide so that said predetermined wavelength is selectively coupled from said first waveguide to said second waveguide wherein said spaced relationship is tailored to provide an interactive strength therebetween in accordance with the formula k(z)=L.sub.) (z)+SL.sub.1 (z)+S.sup.2 L.sub.2 (z)+S.sup.3 L.sub.3 (z) where k(z)=interactive strength, S=sidelobe level in |dB|, and L 0 ,L 1 ,L 2 ,L 3 are functions of the propagation distance (z) so as to suppress spectral sidelobes of said coupled wavelength to a level down to -75 db.
Claim 2
Dependent Claim
111 words
A directional coupler filter comprising: a first waveguide for receiving an optical signal having at least one predetermined wavelength; and a second waveguide in a spaced relationship to said first waveguide so that said predetermined wavelength is selectively coupled from said first waveguide to said second waveguide wherein said spaced relationship is tailored to provide an interactive strength therebetween in accordance with the formula k(z)=L.sub.) (z)+SL.sub.1 (z)+S.sup.2 L.sub.2 (z)+S.sup.3 L.sub.3 (z) where k(z)=interactive strength, S=sidelobe level in |dB|, and L 0 ,L 1 ,L 2 ,L 3 are functions of the propagation distance (z) so as to suppress spectral sidelobes of said coupled wavelength to a level down to -75 db.
Claim 3
Dependent Claim
14 words
A directional coupler filter as defined in claim 1, fabricated in a semiconductor material.
Claim 4
Dependent Claim
17 words
A directional coupler filter as defined in claim 2, said semiconductor material being a III-V alloy compound.
Claim 5
Dependent Claim
17 words
A directional coupler filter as defined in claim 2, said semiconductor material being a II-VI alloy compound.
Claim 6
Dependent Claim
14 words
A directional coupler filter as defined in claim 1, fabricated in a glass material.
Claim 7
Dependent Claim
14 words
A directional coupler filter as defined in claim 1, fabricated in a polymer material.
Claim 8
Dependent Claim
14 words
A directional coupler filter as defined in claim 1, fabricated in a photorefractive material.
Claim 9
Dependent Claim
15 words
A directional coupler filter as defined in claim 7, said photorefractive material being lithium niobate.
Claim 10
Dependent Claim
21 words
A directional coupler filter as defined in claim 1, at least one of said waveguides having gratings to assist the coupling.
Claim 11
Dependent Claim
25 words
A directional coupler filter as defined in claim 1, at least one of said waveguides having electrode means in order to supply injection current thereto.
Claim 12
Dependent Claim
21 words
A directional coupler filter as defined in claim 1, said sidelobe level dependent on the spectral bandwidth of said coupled wavelength.
Claim 13
Dependent Claim
16 words
A directional coupler as defined in claim 11, said spectral bandwidth selected to be a minimum.
Claim 14
Independent Claim
103 words
A method of suppressing the sidelobe levels in an optical directional coupler filter having a first waveguide to receive an optical signal having at least one predetermined wavelength and a second waveguide in spaced relationship to said first waveguide, said predetermined wavelength being selectively coupled to said second waveguide, the method comprising: tailoring the spaced relationship between said first and second waveguides so as to provide an interactive strength according to the formula: k(z)=L.sub.0 (z)+SL.sub.1 (z)+S.sup.2 L.sub.2 (z)+S.sup.3 L.sub.3 (z) wherein k(z)=normalized interactive strength, S=desired sidelobe level in |dB|, and L 0 ,L 1 . . . are functions of propagation distance (z).
Claim 15
Independent Claim
103 words
A method of suppressing the sidelobe levels in an optical directional coupler filter having a first waveguide to receive an optical signal having at least one predetermined wavelength and a second waveguide in spaced relationship to said first waveguide, said predetermined wavelength being selectively coupled to said second waveguide, the method comprising: tailoring the spaced relationship between said first and second waveguides so as to provide an interactive strength according to the formula: k(z)=L.sub.0 (z)+SL.sub.1 (z)+S.sup.2 L.sub.2 (z)+S.sup.3 L.sub.3 (z) wherein k(z)=normalized interactive strength, S=desired sidelobe level in |dB|, and L 0 ,L 1 . . . are functions of propagation distance (z).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-10-08 | 2000-04-08 | 2000-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-08 | 2004-04-08 | 2004-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-08 | 2008-04-08 | 2008-10-08 | $7700.00 | Window Closed / Lapsed |