US5357359A
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All-optical polarization independent optical time division multiplexer and demultiplexer with birefringence compensation
Assignee: NTT Inc
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Filing: 1993-08-11
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Granted: 1994-10-18
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Expires: 2013-08-11
Abstract
Abstract An all-optical polarization independent optical time division multiplexer and demultiplexer which are stable as well as very fast, while being independent of the polarization state of the input optical signal pulses. The demultiplexer has a wavelength-division-multiplexing coupler for wavelength-division-multiplexing time-division-multiplexed optical signal pulses and optical control pulses, and splitting the optical signal pulses at a splitting ratio of 1:1 into two ports, the optical control pulses being in a polarization state in which two orthogonally polarized components have a substantially identical amplitude; an optical Kerr medium with birefringence, for connecting two ports of the wavelength-division-multiplexing coupler, the optical Kerr medium incorporating a birefringence compensation mechanism for compensating a polarization dispersion between two principal axes of the birefringence; and a wavelength division demultiplexer for wavelength-division-demultiplexing time-wise overlapping optical signal pulses and optical control pulses propagated through the optical Kerr medium, to obtain time-division-demultiplexed optical signal pulses. In the multiplexer, the input and output relationship is reversed in the same configuration.
Inventors
- 👤 Kentaro Uchiyama
- 👤 Toshio Morioka
- 👤 Masatoshi Saruwatari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:22
CPC Classifications
H; H04; H04J; H04J14/00; H04J14/08
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
122 words
A polarization independent optical time division demultiplexer, comprising: wavelength-division-multiplexing coupler means for wavelength-division-multiplexing time-division-multiplexed optical signal pulses and optical control pulses, and splitting the optical signal pulses at a splitting ratio of 1:1 into two ports, the optical control pulses being in a polarization state in which two orthogonally polarized components have a substantially identical amplitude; an optical Kerr medium with birefringence, for connecting said two ports of the wavelength-division-multiplexing coupler means, the optical Kerr medium incorporating birefringence compensation means for compensating a polarization dispersion between two principal axes of the birefringence; and wavelength division demultiplexer means for wavelength division demultiplexing time-wise overlapping optical signal pulses and optical control pulses propagated through the optical Kerr medium, to obtain time-division-demultiplexed optical signal pulses.
Claim 2
Dependent Claim
122 words
A polarization independent optical time division demultiplexer, comprising: wavelength-division-multiplexing coupler means for wavelength-division-multiplexing time-division-multiplexed optical signal pulses and optical control pulses, and splitting the optical signal pulses at a splitting ratio of 1:1 into two ports, the optical control pulses being in a polarization state in which two orthogonally polarized components have a substantially identical amplitude; an optical Kerr medium with birefringence, for connecting said two ports of the wavelength-division-multiplexing coupler means, the optical Kerr medium incorporating birefringence compensation means for compensating a polarization dispersion between two principal axes of the birefringence; and wavelength division demultiplexer means for wavelength division demultiplexing time-wise overlapping optical signal pulses and optical control pulses propagated through the optical Kerr medium, to obtain time-division-demultiplexed optical signal pulses.
Claim 3
Dependent Claim
24 words
The demultiplexer of claim 1, wherein the birefringence compensation means comprises cross-splicing at 90° of two polarization maintaining optical fibers of an identical length.
Claim 4
Dependent Claim
29 words
The demultiplexer of claim 1, wherein the birefringence compensation means comprises a connection of two polarization maintaining optical fibers of an identical length with a λ/2 plate inserted therebetween.
Claim 5
Dependent Claim
30 words
The demultiplexer of claim 1, wherein the birefringence compensation means comprises a connection of two polarization maintaining optical fibers of an identical length with a 90° Faraday rotator inserted therebetween.
Claim 6
Dependent Claim
70 words
The demultiplexer of claim 1, wherein the optical control pulses are in forms of sampling optical pulses having a repetition frequency different from an 1/N divided frequency of a repetition frequency of the optical signal pulses by a prescribed amount, where N is an integer, such that an envelope of an output of the wavelength division demultiplexer means indicates a time-wise enlarged waveform of each of the optical signal pulses.
Claim 7
Dependent Claim
86 words
The demultiplexer of claim 1, wherein the wavelength-division-multiplexing coupler means further comprises: wavelength division multiplexer for wavelength-division-multiplexing the time-division-multiplexed optical signal pulses and the optical control pulses; and optical coupler for coupling the optical signal pulses and the optical control pulses which are wavelength-division-multiplexed by the wavelength division multiplexer into said two ports by splitting the optical signal pulses at the splitting ratio of 1:1 into said two ports and the optical control pulses at a splitting ratio of 1:0 into one of said two ports.
Claim 8
Dependent Claim
148 words
The demultiplexer of claim 1, wherein the wavelength-division-multiplexing coupler means further comprises: optical coupler having two output ports corresponding to said two ports of the wavelength-division-multiplexing coupler means, for coupling the optical signal pulses into said two output ports by splitting the optical signal pulses at the splitting ratio of 1:1 into said two output ports; and wavelength division multiplexer, connected between the one of said two output ports of the optical coupler means and the optical Kerr medium, for wavelength division multiplexing the time-division-multiplexed optical signal pulses split into said one of said two output ports of the optical coupler means and the optical control pulses and supplying the wavelength-division-multiplexed optical signal pulses and optical control pulses into the optical Kerr medium through one of said two ports of the wavelength-division-multiplexing coupler means corresponding to said one of said two output ports of the optical coupler means.
Claim 9
Dependent Claim
31 words
The demultiplexer of claim 7, wherein the wavelength division demultiplexer means is connected between another one of said two output ports of the optical coupler means and the optical Kerr medium.
Claim 10
Dependent Claim
22 words
The demultiplexer of claim 1, further comprising: optical circulator means for supplying the time-division-multiplexed optical signal pulses to the wavelength-division-multiplexing coupler means.
Claim 11
Dependent Claim
34 words
The demultiplexer of claim 9, wherein the optical circulator means receives the optical signal pulses not overlapping with the optical control pulses and propagated through the optical Kerr medium from the wavelength-division-multiplexing coupler means.
Claim 12
Dependent Claim
152 words
A polarization independent optical time division multiplexer, comprising: wavelength-division-multiplexing coupler means for wavelength-division-multiplexing time-division-multiplexed first optical signal pulses and optical control pulses, and splitting the first optical signal pulses at a splitting ratio of 1:1 into two ports, the optical control pulses being in a polarization state in which two orthogonally polarized components have a substantially identical amplitude; an optical Kerr medium with birefringence, for connecting said two ports of the wavelength-division-multiplexing coupler means, the optical Kerr medium incorporating birefringence compensation means for compensating a polarization dispersion between two principal axes of the birefringence; and wavelength division demultiplexer means for supplying time-division-multiplexed second optical signal pulses to the optical Kerr medium through the wavelength-division-multiplexing coupler means; wherein time-division-multiplexed optical signal pulses in which the first and second optical signal pulses are time-division-multiplexed at the optical Kerr medium are outputted from one of the wavelength-division-multiplexing coupler means and the wavelength division demultiplexer means.
Claim 13
Dependent Claim
152 words
A polarization independent optical time division multiplexer, comprising: wavelength-division-multiplexing coupler means for wavelength-division-multiplexing time-division-multiplexed first optical signal pulses and optical control pulses, and splitting the first optical signal pulses at a splitting ratio of 1:1 into two ports, the optical control pulses being in a polarization state in which two orthogonally polarized components have a substantially identical amplitude; an optical Kerr medium with birefringence, for connecting said two ports of the wavelength-division-multiplexing coupler means, the optical Kerr medium incorporating birefringence compensation means for compensating a polarization dispersion between two principal axes of the birefringence; and wavelength division demultiplexer means for supplying time-division-multiplexed second optical signal pulses to the optical Kerr medium through the wavelength-division-multiplexing coupler means; wherein time-division-multiplexed optical signal pulses in which the first and second optical signal pulses are time-division-multiplexed at the optical Kerr medium are outputted from one of the wavelength-division-multiplexing coupler means and the wavelength division demultiplexer means.
Claim 14
Dependent Claim
24 words
The multiplexer of claim 11, wherein the birefringence compensation means comprises cross-splicing at 90° of two polarization maintaining optical fibers of an identical length.
Claim 15
Dependent Claim
29 words
The multiplexer of claim 11, wherein the birefringence compensation means comprises a connection of two polarization maintaining optical fibers of an identical length with a λ/2 plate inserted therebetween.
Claim 16
Dependent Claim
30 words
The multiplexer of claim 11, wherein the birefringence compensation means comprises a connection of two polarization maintaining optical fibers of an identical length with a 90° Faraday rotator inserted therebetween.
Claim 17
Dependent Claim
89 words
The multiplexer of claim 11, wherein the wavelength-division-multiplexing coupler means further comprises: wavelength division multiplexer for wavelength-division-multiplexing the time-division-multiplexed first optical signal pulses and the optical control pulses; and optical coupler for coupling the first optical signal pulses and the optical control pulses which are wavelength-division-multiplexed by the wavelength division multiplexer into said two ports by splitting the first optical signal pulses at the splitting ratio of 1:1 into said two ports and the optical control pulses at a splitting ratio of 1:0 into one of said two ports.
Claim 18
Dependent Claim
148 words
The multiplexer of claim 11, wherein the wavelength-division-multiplexing coupler means further comprises: optical coupler having two output ports corresponding to said two ports of the wavelength-division-multiplexing coupler means, for coupling the first optical signal pulses into said two output ports by splitting the optical signal pulses at the splitting ratio of 1:1 into said two output ports; and wavelength division multiplexer, connected between one of said two output ports of the optical coupler means and the optical Kerr medium, for wavelength-division-multiplexing the time-division-multiplexed first optical signal pulses split into said one of said two output ports of the optical coupler means and the optical control pulses and supplying the wavelength-division-multiplexed first optical signal pulses and optical control pulses into the optical Kerr medium through one of said two ports of the wavelength-division-multiplexing coupler means corresponding to said one of said two output ports of the optical coupler means.
Claim 19
Dependent Claim
31 words
The multiplexer of claim 16, wherein the wavelength division demultiplexer means is connected between another one of said two output ports of the optical coupler means and the optical Kerr medium.
Claim 20
Dependent Claim
41 words
The multiplexer of claim 11, further comprising: optical circulator means for supplying one of the time-division-multiplexed first optical signal pulses and the time-division-multiplexed second optical signal pulses to said one of the wavelength-division-multiplexing coupler means and the wavelength division demultiplexer means.
Claim 21
Dependent Claim
30 words
The demultiplexer of claim 18, wherein the optical circulator means receives the time-division-multiplexed optical signal pulses from said one of the wavelength-division-multiplexing coupler means and the wavelength division demultiplexer means.
Claim 22
Dependent Claim
76 words
The multiplexer of claim 18, wherein the optical circulator means supplies said one of the time-division-multiplexed first optical signal pulses and the time-division-multiplexed second optical signal pulses to said one of the wavelength-division-multiplexing coupler means and the wavelength division demultiplexer means at such timings that the optical control pulses and said one of the time-division-multiplexed first optical signal pulses and the time-division-multiplexed second optical signal pulses overlap with each other time-wise in the optical Kerr medium.
References Cited (Backward Citations)
US4761050A
Cited
JPS63157133A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-17 | 1998-04-18 | 1998-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-17 | 2002-04-18 | 2002-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-17 | 2006-04-18 | 2006-10-18 | $7700.00 | Window Closed / Lapsed |