Patent US6055078A successfully refreshed from Google Patents.
US6055078A
Expired / Lapsed
US
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Real time wavelength monitoring circuit
Assignee: University of Maryland, Baltimore County
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Filing: 1998-05-01
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Granted: 2000-04-25
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Expires: 2018-05-01
Abstract
Abstract A real time multi-channel wavelength monitoring circuit for monitoring Waveguide Division Multiplexing communications networks (WDM) is disclosed. The monitoring circuit monitors the full wavelength of an input signal by providing center offset inputs into a Phased Array Waveguide Grating (PAWG). By providing center offset inputs to a PAWG the passband crossover point can be changed optimizing a different dynamic range and wavelength resolution.
Inventors
- 👤 Yung Jui Chen
- 👤 Haifeng Li
- 👤 Shan Zhong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:52
CPC Classifications
H; H04; H04J; H04J14/00; H04J14/02; G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/12007; G02B6/12009; G02B6/12019; H04B; H04B10/00; H04B10/07; H04B10/075; H04B10/079; H04B10/0795; H04B10/07957; H04B10/50; H04B10/501; H04B10/506; H04B10/572
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
102 words
A multi-channel wavelength monitoring circuit for monitoring signals comprising; an input means for receiving signals at a first center wavelength offset input and a second center wavelength offset input wherein each of said signals has an input signal wavelength; a Phased Array Waveguide Grating (PAWG) connected to said input means; and a switching means for switching said input means to receive said signals between said first center wavelength offset input and said second center wavelength offset input whereby said switching means switches between said first and second wavelength offsets in order to monitor each input signal wavelength over an entire wavelength range.
Claim 2
Dependent Claim
102 words
A multi-channel wavelength monitoring circuit for monitoring signals comprising; an input means for receiving signals at a first center wavelength offset input and a second center wavelength offset input wherein each of said signals has an input signal wavelength; a Phased Array Waveguide Grating (PAWG) connected to said input means; and a switching means for switching said input means to receive said signals between said first center wavelength offset input and said second center wavelength offset input whereby said switching means switches between said first and second wavelength offsets in order to monitor each input signal wavelength over an entire wavelength range.
Claim 3
Dependent Claim
42 words
A multi-channel wavelength monitoring circuit as claimed in claim 1 wherein connected to a first end of said PAWG is said first center wavelength offset input, and connected to a second side of said PAWG is said second center wavelength offset input.
Claim 4
Dependent Claim
21 words
A multi-channel wavelength monitoring circuit as claimed in claim 1 and further comprising a plurality of detectors connected to said PAWG.
Claim 5
Dependent Claim
23 words
A multi-channel wavelength monitoring circuit as claimed in claim 3 and further comprising a plurality of amplifiers connected to said plurality of detectors.
Claim 6
Dependent Claim
22 words
A multi-channel wavelength monitoring circuit as claimed in claim 4 and further comprising an A/D converter connected to said plurality of amplifiers.
Claim 7
Dependent Claim
42 words
A multi-channel wavelength monitoring circuit as claimed in claim 5 wherein connected to said A/D converter is a control means for switching said switch means whereby said control means switches said switching means when an output is detected from said A/D converter.
Claim 8
Dependent Claim
20 words
A multi-channel wavelength monitoring circuit as claimed in claim 5 wherein connected to said switching means is said control means.
Claim 9
Dependent Claim
74 words
A multi-channel wavelength monitoring circuit as claimed in claim 1 wherein said first center wavelength offset satisfies the equation λ=λ.sub.0 -(2n.sub.s dsin(β)/m)/2 and said second center wavelength offset satisfies the equation λ=λ.sub.0 +(2n.sub.s dsin(β)/m)/2 where λ 0 is the center wavelength; and 2n s dsin(β)/m is the center wavelength offset where n s is the slab waveguide index; d is the grating pitch; β is the incident angle; and m is the grating order.
Claim 10
Dependent Claim
33 words
A multi-channel wavelength monitoring circuit as claimed in claim 1 further comprising a supply unit connected to said input means wherein said supply unit provides an input for said monitoring unit to process.
Claim 11
Dependent Claim
18 words
A multi-channel wavelength monitoring circuit as claimed in claim 9 wherein said supply unit is a tunable laser.
Claim 12
Dependent Claim
20 words
A multi-channel wavelength monitoring circuit as claimed in claim 9 wherein said supply unit is a precision wavelength addressable laser.
Claim 13
Dependent Claim
19 words
A multi-channel wavelength monitoring circuit as claimed in claim 9 wherein said supply unit is a tunable diode laser.
Claim 14
Dependent Claim
30 words
A multi-channel wavelength monitoring circuit as claimed in claim 9 wherein said switching means is connected to said supply unit and said switching means provides information to said supply unit.
References Cited (Backward Citations)
US4942568A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-04-25 | 2003-10-25 | 2004-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-04-25 | 2007-10-25 | 2008-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-04-25 | 2011-10-25 | 2012-04-25 | $7700.00 | Window Closed / Lapsed |