EP0265233A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Non-linear optical device
Assignee: British Telecommunications PLC
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Filing: 1987-10-20
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Granted: —
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Expires: 2007-10-20
Abstract
Abstract An optical device comprises an optical waveguide (2) formed from at least a first material having a non-linear refractive index n₂ coupled to a first pair of ports (4,5) of an optical coupler (3). An optical signal input at one of the second pair of ports (6,7) of the coupler (3) is split two provide two signals counter propagating around the waveguide loop (2). By selecting the coupling ratio and appropriate waveguide parameters to ensure an asymmetry in the device it is possible to produce an intensity dependent relative phase shift between the counter propagating signals, thereby to vary the device output. Embodiments of the invention may be used to perform logic functions on, to amplify, switch or otherwise modify an input signal.
Inventors
- 👤 Nicholas John Doran
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:34
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/3515; G02F1/3517; G02F1/3519; G02F3/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
130 words
An optical device comprising a coupling means having first and second pairs of optical communication ports, in which portions of an optical signal received at a port of one pair are coupled into each port of the other pair in a predetermined coupling ratio; and an optical waveguide at least a portion of which includes a first material having a non-linear refractive index, the optical waveguide coupling together the first pair of ports; the coupling ratio and appropriate waveguide parameters being selected such that in use the portions of an optical signal at a working intensity received at one of the second pair of ports of the coupling means and coupled into each end of the waveguide return with an intensity dependent relative phase shift after travelling around the waveguide.
Claim 2
Dependent Claim
130 words
An optical device comprising a coupling means having first and second pairs of optical communication ports, in which portions of an optical signal received at a port of one pair are coupled into each port of the other pair in a predetermined coupling ratio; and an optical waveguide at least a portion of which includes a first material having a non-linear refractive index, the optical waveguide coupling together the first pair of ports; the coupling ratio and appropriate waveguide parameters being selected such that in use the portions of an optical signal at a working intensity received at one of the second pair of ports of the coupling means and coupled into each end of the waveguide return with an intensity dependent relative phase shift after travelling around the waveguide.
Claim 3
Dependent Claim
18 words
A device according to claim 1, wherein the coupling ratio of the coupling means is other than 50:50.
Claim 4
Dependent Claim
43 words
A device according to claim 1 or claim 2, wherein the waveguide further comprises a second material in series with the first material, the first and second materials having non-commuting effects on an optical signal at a working intensity travelling along the waveguide.
Claim 5
Dependent Claim
18 words
A device according to claim 3, where the second material is relatively more dispersive than the first material.
Claim 6
Dependent Claim
20 words
A device according to claim 1 or claim 2, wherein the optical waveguide is formed from a single optical fibre.
Claim 7
Dependent Claim
57 words
An optical device according to any preceding claim wherein the waveguide comprises material which supports soliton effects when optical pulses at appropriate working intensities are injected into the device, the length of the waveguide being sufficient such that the intensity dependent phase of an injected pulse is substantially uniform throughout the pulse after propagation through the waveguide.
Claim 8
Dependent Claim
23 words
An optical device according to any preceding claim wherein the non-linear material is provided as an overlay on a portion of the waveguide.
Claim 9
Dependent Claim
55 words
An optical amplifier including an optical device according to any of the preceding claims; additional coupling means having a pair of input ports and an output port optically coupled with a second port of the one coupling means; and a bias signal source coupled with one of the input ports of the additional coupling means.
Claim 10
Dependent Claim
16 words
An optical logic gate including a device according to any one of claims 1 to 7.
Claim 11
Independent Claim
57 words
A method of processing an optical signal comprising the steps of: providing a device according to any preceding claim; inputting an optical signal into a second port of the device to produce two counter propagating signals within the waveguide, thereby to provide a processed pulse signal output at least at one of the second pair of ports.
Claim 12
Dependent Claim
24 words
A method according to claim 10 comprising inputting an optical signal having a duration less than the transit time for propagation around the waveguide.
Claim 13
Dependent Claim
91 words
A method according to claim 10 for processing an optical signal comprising pulses capable of soliton propagation comprising the steps of: providing a device according to the invention in its first aspect including a waveguide whose parameters are selected for soliton propagation; inputting a pulse signal into a second port of the device, at an amplitude appropriate for soliton propagation in the waveguide, thereby to produce two counter propagating signals within the waveguide and to provide a processed pulse signal output at least at one of the second pair of ports.
References Cited (Backward Citations)
No citation records indexed.
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