US6163393A
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Method and apparatus for wavelength multipexing/demultiplexing
Assignee: EZconn Corp
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Filing: 1999-03-22
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Granted: 2000-12-19
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Expires: 2019-03-22
Abstract
Abstract A wavelength division multiplexing/demultiplexing device is presented utilizing a polarization-based filter to obtain a flat-top filter response which can be utilized to create a flat-top slicer which separates out odd and even wavelengths, or upper and lower channels of an input signal. The polarization-based filter provides superior peak flatness and isolation for narrow channel spacings over what can be obtained in traditional interferometric devices. The flat-top slicer can be used as the first stage of a cascade of WDM devices in which following stages can be based on polarization-based filters or traditional interferometric WDM devices, which are adequate due to the increased channel spacing obtained in the first stage of the cascade.
Inventors
- 👤 Kuang-Yi Wu
- 👤 Jian-Yu Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:11
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/27; G02B6/2706; G02B6/2713; G02B6/272; G02B6/28; G02B6/293; G02B6/29302; G02B6/29346; G02B6/29358; G02B6/29379; G02B6/2938; G02B6/29386; G02B6/29392; G02B6/29394; G02F; G02F1/00; G02F1/29; G02F1/31; H; H04; H04J; H04J14/00; H04J14/02; H04J14/06; H04Q; H04Q11/00; H04Q11/0001; H04Q11/0003; H04Q11/0005; H04Q2011/0007; H04Q2011/0009; H04Q2011/0016; H04Q2011/0024; H04Q2011/0026; H04Q2011/0032; H04Q2011/0035
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
153 words
A method of demultiplexing an input optical signal having a plurality of wavelengths, said method comprising the steps of: filtering the input optical signal using a polarization filter to produce a first subset of wavelengths at a first polarization and a second subset of wavelengths at a second polarization, wherein said polarization filter has a substantially flat transmission function in a wavelength region immediately surrounding each of a first plurality of transmission peaks and provides high isolation between first plurality of transmission peaks; spatially separating said first and second subsets of wavelengths based on their polarizations; and demultiplexing said first subset of wavelengths to produce at least a third subset and a fourth subset of wavelengths using a wavelength demultiplexing device having a transmission function having a second plurality of transmission peaks, wherein said first plurality of transmission peaks have substantially flatter transmissions and higher isolation than said second plurality of transmission peaks.
Claim 2
Independent Claim
153 words
A method of demultiplexing an input optical signal having a plurality of wavelengths, said method comprising the steps of: filtering the input optical signal using a polarization filter to produce a first subset of wavelengths at a first polarization and a second subset of wavelengths at a second polarization, wherein said polarization filter has a substantially flat transmission function in a wavelength region immediately surrounding each of a first plurality of transmission peaks and provides high isolation between first plurality of transmission peaks; spatially separating said first and second subsets of wavelengths based on their polarizations; and demultiplexing said first subset of wavelengths to produce at least a third subset and a fourth subset of wavelengths using a wavelength demultiplexing device having a transmission function having a second plurality of transmission peaks, wherein said first plurality of transmission peaks have substantially flatter transmissions and higher isolation than said second plurality of transmission peaks.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said first subset of wavelengths includes every other wavelength in the input optical signal.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein said first subset of wavelengths includes a lower set of wavelengths from the input optical signal.
Claim 5
Dependent Claim
37 words
The method of claim 1 wherein the spacing of the wavelengths of said third subset of wavelengths is larger than the spacing of the wavelengths of the input optical signal by a factor of 2 N .
Claim 6
Dependent Claim
11 words
The method of claim 4 wherein N is equal to 2.
Claim 7
Independent Claim
166 words
An apparatus for demultiplexing an input optical signal having multiple wavelengths, said apparatus comprising: a polarization-based wavelength routing device having: (a) a first output port; (b) a second output port; (c) a polarization filter having a first transmission function with a first plurality of transmission peaks forming a first subset of wavelengths and a second subset of wavelengths from the input optical signal; (d) a polarization-dependent routing element routing said first subset of wavelengths to said first output port and routing said second subset of wavelengths to said second output port; and a second wavelength routing device receiving said first subset of wavelengths and producing a third subset of wavelengths at a third output port and a fourth subset of wavelengths at a fourth output port, wherein said second wavelength routing device has a second transmission function with a second plurality of transmission peaks, wherein said first plurality of transmission peaks have substantially flatter peak transmissions and higher isolation than said second plurality of transmission peaks.
Claim 8
Independent Claim
166 words
An apparatus for demultiplexing an input optical signal having multiple wavelengths, said apparatus comprising: a polarization-based wavelength routing device having: (a) a first output port; (b) a second output port; (c) a polarization filter having a first transmission function with a first plurality of transmission peaks forming a first subset of wavelengths and a second subset of wavelengths from the input optical signal; (d) a polarization-dependent routing element routing said first subset of wavelengths to said first output port and routing said second subset of wavelengths to said second output port; and a second wavelength routing device receiving said first subset of wavelengths and producing a third subset of wavelengths at a third output port and a fourth subset of wavelengths at a fourth output port, wherein said second wavelength routing device has a second transmission function with a second plurality of transmission peaks, wherein said first plurality of transmission peaks have substantially flatter peak transmissions and higher isolation than said second plurality of transmission peaks.
Claim 9
Dependent Claim
20 words
The apparatus of claim 6 wherein said first subset of wavelengths includes every other wavelength in the input optical signal.
Claim 10
Dependent Claim
22 words
The apparatus of claim 6 wherein said first subset of wavelengths includes a lower set of wavelengths from the input optical signal.
Claim 11
Dependent Claim
37 words
The apparatus of claim 6 wherein the spacing of the wavelengths of said third subset of wavelengths is larger than the spacing of the wavelengths of the input optical signal by a factor of 2 N .
Claim 12
Dependent Claim
11 words
The apparatus of claim 9 wherein N is equal to 2.
Claim 13
Dependent Claim
27 words
The apparatus of claim 6 wherein the bandwidth of said second plurality of transmission peaks is approximately twice the bandwidth of said first plurality of transmission peaks.
Claim 14
Dependent Claim
16 words
The apparatus of claim 6 wherein said second wavelength routing device comprises an arrayed waveguide device.
Claim 15
Dependent Claim
17 words
The apparatus of claim 6 wherein said second wavelength routing device comprises a fused biconical taper device.
Claim 16
Dependent Claim
16 words
The apparatus of claim 6 wherein said second wavelength routing device comprises a diffraction grating device.
Claim 17
Dependent Claim
17 words
The apparatus of claim 6 wherein said second wavelength routing device comprises a fiber Bragg grating device.
Claim 18
Dependent Claim
16 words
The apparatus of claim 6 wherein said second wavelength routing device comprises a thin-film interference filter.
Claim 19
Dependent Claim
17 words
The apparatus of claim 6 wherein said second wavelength routing device comprises a polarization-based wavelength routing device.
Claim 20
Independent Claim
194 words
An apparatus for demultiplexing an input optical signal having multiple wavelengths, said apparatus comprising: a polarization-based wavelength routing device having: (a) a polarization separation and conversion stage converting the input optical signal to a plurality of polarized beams; (b) a wavelength-dependent polarization filter selectively changing the polarization of components of said polarized beams based on their wavelength, said wavelength-dependent polarization filter having a first transmission function with a first plurality of transmission peaks forming a first subset of wavelengths and a second set of wavelengths; (c) a polarization routing stage spatially separating said components containing said first subset of wavelengths from components containing said second subset of wavelengths based on their polarizations; and (d) a polarization conversion and recombination stage combining said components containing said first subset of wavelengths; and a second wavelength routing device receiving said first subset of wavelengths and outputting a third subset of wavelengths and a fourth subset of wavelengths, wherein said second wavelength routing device has a second transmission function having a second plurality of transmission peaks wherein said first plurality of transmission peaks have substantially flatter peak transmissivities and higher isolation than said second plurality of transmission peaks.
Claim 21
Independent Claim
194 words
An apparatus for demultiplexing an input optical signal having multiple wavelengths, said apparatus comprising: a polarization-based wavelength routing device having: (a) a polarization separation and conversion stage converting the input optical signal to a plurality of polarized beams; (b) a wavelength-dependent polarization filter selectively changing the polarization of components of said polarized beams based on their wavelength, said wavelength-dependent polarization filter having a first transmission function with a first plurality of transmission peaks forming a first subset of wavelengths and a second set of wavelengths; (c) a polarization routing stage spatially separating said components containing said first subset of wavelengths from components containing said second subset of wavelengths based on their polarizations; and (d) a polarization conversion and recombination stage combining said components containing said first subset of wavelengths; and a second wavelength routing device receiving said first subset of wavelengths and outputting a third subset of wavelengths and a fourth subset of wavelengths, wherein said second wavelength routing device has a second transmission function having a second plurality of transmission peaks wherein said first plurality of transmission peaks have substantially flatter peak transmissivities and higher isolation than said second plurality of transmission peaks.
Claim 22
Dependent Claim
20 words
The apparatus of claim 18 wherein said first subset of wavelengths includes every other wavelength in the input optical signal.
Claim 23
Dependent Claim
22 words
The apparatus of claim 18 wherein said first subset of wavelengths includes a lower set of wavelengths from the input optical signal.
Claim 24
Dependent Claim
37 words
The apparatus of claim 18 wherein the spacing of the wavelengths of said third subset of wavelengths is larger than the spacing of the wavelengths of the input optical signal by a factor of 2 N .
Claim 25
Dependent Claim
11 words
The apparatus of claim 21 wherein N is equal to 2.
Claim 26
Dependent Claim
16 words
The apparatus of claim 18 wherein said wavelength-dependent polarization filter comprises a plurality of birefringent elements.
Claim 27
Dependent Claim
14 words
The apparatus of claim 18 wherein said wavelength-dependent polarization filter comprises a polarization fiber.
Claim 28
Dependent Claim
16 words
The apparatus of claim 18 wherein said wavelength-dependent polarization filter comprises a plurality of birefringent plates.
Claim 29
Dependent Claim
15 words
The apparatus of claim 25 wherein said plurality of birefringent plates comprise a crystalline material.
Claim 30
Dependent Claim
11 words
The apparatus of claim 26 wherein said crystalline material comprises calcite.
Claim 31
Dependent Claim
18 words
The apparatus of claim 18 wherein said polarization-based wavelength routing device further comprises a polarization mode dispersion compensator.
Claim 32
Independent Claim
250 words
An apparatus for wavelength demultiplexing an optical signal having a plurality of wavelengths, said apparatus comprising: a first stage wavelength routing device having an input port and a plurality of output ports, wherein said first stage wavelength routing device provides transmission functions associated with each path from said input port to each of said output ports, and wherein each of said transmission functions is defined by a set of Fourier components providing a substantially flat transmission function from said input port to one of said output ports in a wavelength region immediately surrounding each of a first plurality of transmission peaks and high isolation between said first plurality of transmission peaks; and a second stage wavelength routing device having a second stage input port connected to one of said first stage output ports, and a plurality of second stage output ports, wherein said second stage wavelength routing device provides transmission functions associated with each path from said second stage input port to each of said second stage output ports, and wherein each of said second stage transmission functions is defined by a set of Fourier components providing a transmission function from said second stage input port to one of said second stage output ports with a second plurality of transmission peaks, wherein said first set of Fourier components is selected such that said first stage transmission functions have substantially flatter peaks and substantially steeper roll-offs than said second stage transmission functions as defined by said second set of Fourier components.
Claim 33
Independent Claim
250 words
An apparatus for wavelength demultiplexing an optical signal having a plurality of wavelengths, said apparatus comprising: a first stage wavelength routing device having an input port and a plurality of output ports, wherein said first stage wavelength routing device provides transmission functions associated with each path from said input port to each of said output ports, and wherein each of said transmission functions is defined by a set of Fourier components providing a substantially flat transmission function from said input port to one of said output ports in a wavelength region immediately surrounding each of a first plurality of transmission peaks and high isolation between said first plurality of transmission peaks; and a second stage wavelength routing device having a second stage input port connected to one of said first stage output ports, and a plurality of second stage output ports, wherein said second stage wavelength routing device provides transmission functions associated with each path from said second stage input port to each of said second stage output ports, and wherein each of said second stage transmission functions is defined by a set of Fourier components providing a transmission function from said second stage input port to one of said second stage output ports with a second plurality of transmission peaks, wherein said first set of Fourier components is selected such that said first stage transmission functions have substantially flatter peaks and substantially steeper roll-offs than said second stage transmission functions as defined by said second set of Fourier components.
Claim 34
Dependent Claim
24 words
The apparatus of claim 29 wherein said first stage wavelength routing device further comprises a polarization filter determining said first set of Fourier components.
Claim 35
Dependent Claim
28 words
The apparatus of claim 30 wherein said second set of Fourier components is determined by interferometric effects between propagating optical signals in said second stage wavelength routing device.
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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) | 2003-12-19 | 2004-06-19 | 2004-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-12-19 | 2008-06-19 | 2008-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-12-19 | 2012-06-19 | 2012-12-19 | $7700.00 | Window Closed / Lapsed |