US5022734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of modifying an optical waveguide and waveguide so modified
Assignee: British Telecommunications PLC
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Filing: 1988-09-21
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Granted: 1991-06-11
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Expires: 2008-09-21
Abstract
Abstract A method of structurally modifying a silica monomode optical fiber (4) by launching optical power into the fiber (4) from an Nd:YAG laser operating at 1.064 μm and raising the temperature of a portion of the fiber (4) by bringing a metal film (12) into contact with a polished half-coupler block (6) to absorb energy from the laser (2). A structural modification of the fiber is initiated which propagates towards the laser (2) sustained by the optical power. It provides a means of decommissioning an optical fiber. The modified optical fiber (4) has regular periodic damage sites which can be used to form a diffraction grating. The method may also be used as an optical power limiter to protect optical networks from too high optical power inputs.
Inventors
- 👤 Raman Kashyap
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:02
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/255; G02B6/2552; B; B23; B23K; B23K26/00; B23K26/50; B23K26/53; C; C03; C03B; C03B37/00; C03B37/10; C03B37/14; C03B37/15; G02B6/02; G02B6/02057; G02B6/02076; G02B6/02123; G02B6/02128
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
71 words
An optical waveguide network couplable to a source of optical power, said network including a first optical waveguide coupled in series to an optical device, said device having a damage threshold, said first optical waveguide being arranged such that the propagation of a structural modification along the waveguide towards said source of optical power will be initiated and sustained at an optical power below said damage threshold of the optical device.
Claim 2
Dependent Claim
71 words
An optical waveguide network couplable to a source of optical power, said network including a first optical waveguide coupled in series to an optical device, said device having a damage threshold, said first optical waveguide being arranged such that the propagation of a structural modification along the waveguide towards said source of optical power will be initiated and sustained at an optical power below said damage threshold of the optical device.
Claim 3
Dependent Claim
18 words
An optical network as claimed in claim 1 in which the optical device is a second optical waveguide.
Claim 4
Dependent Claim
35 words
An optical network as claimed in claim 2 in which said damage threshold of the second optical waveguide is the optical power necessary to sustain the propagation of a structural modification along said second waveguide.
Claim 5
Dependent Claim
40 words
An optical network as claimed in claim 1 or 3 in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a power of said first optical waveguide.
Claim 6
Dependent Claim
48 words
An optical network as claimed in claims 1 or 3 in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide wherein said first waveguide is an optical fibre.
Claim 7
Dependent Claim
49 words
An optical network as claimed in claims 1 or 3 in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide wherein said first waveguide is a monomode optical fibre.
Claim 8
Dependent Claim
59 words
An optical network as claimed in claims 1 or 3 in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which the rise in temperature is caused by a material absorbing the optical power near the first waveguide.
Claim 9
Dependent Claim
59 words
An optical network as claimed in claims 1 or 3 in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which the rise in temperature is caused by placing an absorber at the end of the first waveguide.
Claim 10
Dependent Claim
54 words
An optical network as claimed in claims 1 or 3 in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which the rise in temperature is caused by an externally applied heat source.
Claim 11
Dependent Claim
52 words
An optical network as claimed in claims 1 or 3 in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which the rise in temperature is caused by a fusion splicer.
Claim 12
Dependent Claim
48 words
An optical network as claimed in claims 1 or 3 in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which said source is a mode-locked laser.
Claim 13
Dependent Claim
134 words
An optical network couplable to a source of optical power, said network including: a first optical waveguide coupled in series to an optical device, said device having a damage threshold; said first optical waveguide being arranged such that the propagation of a structural modification along the waveguide towards said source of optical power will be initiated and sustained at an optical power below said damage threshold of the optical device; in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which the rise in temperature is caused by bringing a metal film into contact with a polished half coupler-block so as to cause the metal film to absorb energy from said optical source.
Claim 14
Dependent Claim
134 words
An optical network couplable to a source of optical power, said network including: a first optical waveguide coupled in series to an optical device, said device having a damage threshold; said first optical waveguide being arranged such that the propagation of a structural modification along the waveguide towards said source of optical power will be initiated and sustained at an optical power below said damage threshold of the optical device; in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which the rise in temperature is caused by bringing a metal film into contact with a polished half coupler-block so as to cause the metal film to absorb energy from said optical source.
Claim 15
Dependent Claim
112 words
An optical network couplable to a source of optical power, said network including: a first optical waveguide coupled in series to an optical device, said device having a damage threshold; said first optical waveguide being arranged such that the propagation of a structural modification along the waveguide towards said source of optical power will be initiated and sustained at an optical power below said damage threshold of the optical device; in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which said source is a Nd:YAG laser operating at 1.064 μm.
Claim 16
Dependent Claim
112 words
An optical network couplable to a source of optical power, said network including: a first optical waveguide coupled in series to an optical device, said device having a damage threshold; said first optical waveguide being arranged such that the propagation of a structural modification along the waveguide towards said source of optical power will be initiated and sustained at an optical power below said damage threshold of the optical device; in which the structural modification is initiated and sustained by launching optical power into the optical waveguide network and raising the temperature of a portion of said first optical waveguide in which said source is a Nd:YAG laser operating at 1.064 μm.
Claim 17
Dependent Claim
92 words
An optical power limiter for use in limiting the level of optical power applied to an optical device having a damage threshold power above which the device is susceptible of permanent damage, said power limiter comprising: an optical waveguide having a predetermined damage threshold power lower that of said optical device, said waveguide having a core which is periodically spatially interrupted upon passage of optical power in excess of said predetermined damage threshold power; and means for connecting said optical waveguide in series between said optical device and optical power applied thereto.
Claim 18
Dependent Claim
92 words
An optical power limiter for use in limiting the level of optical power applied to an optical device having a damage threshold power above which the device is susceptible of permanent damage, said power limiter comprising: an optical waveguide having a predetermined damage threshold power lower that of said optical device, said waveguide having a core which is periodically spatially interrupted upon passage of optical power in excess of said predetermined damage threshold power; and means for connecting said optical waveguide in series between said optical device and optical power applied thereto.
Claim 19
Dependent Claim
20 words
An optical power limiter as in claim 14 wherein said optical waveguide and said optical device are both optical fibers.
Claim 20
Dependent Claim
92 words
An optical waveguide network comprising: at least one source of optical signal power; at least one optical signal processing device; a first optical waveguide having a predetermined damage threshold power; and a second optical waveguide; said source and processing device being optically coupled via said first and second optical waveguides, said first optical waveguide being interposed between the source and at least one of the said processing device and the said second optical waveguide so as to protect against application of optical power thereto in excess of said predetermined damage threshold power.
Claim 21
Dependent Claim
92 words
An optical waveguide network comprising: at least one source of optical signal power; at least one optical signal processing device; a first optical waveguide having a predetermined damage threshold power; and a second optical waveguide; said source and processing device being optically coupled via said first and second optical waveguides, said first optical waveguide being interposed between the source and at least one of the said processing device and the said second optical waveguide so as to protect against application of optical power thereto in excess of said predetermined damage threshold power.
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) | 1994-06-10 | 1994-12-10 | 1995-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-10 | 1998-12-10 | 1999-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-10 | 2002-12-10 | 2003-06-11 | $7700.00 | Window Closed / Lapsed |