Patent US3500178A successfully refreshed from Google Patents.
EP0146262A2
Expired / Lapsed
EP
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Optical amplifier
Assignee: Nortel Networks Ltd
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Filing: 1984-11-14
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Granted: —
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Expires: 2004-11-14
Abstract
Abstract @ Use is made of stimulated Raman emission to induce gain in an optical signal (13) of a first wavelength. The optical signal (13) and a pump signal (14) are synchronously coupled to a length of optical fibre (15). The pump signal is at a second wavelength. The first wavelength corresponds to one Stokes shift from the pump signal. The pump signal is generated by a semiconductor laser (11) and thus only relatively low pump powers are involved in comparison with the conventional use of YAG lasers as the pumps, however significant gain is achieved despite the low pump powers. Preferably the optical fibre (15) has a high Raman cross-section and a low transmission loss, for example GeO 2 doped SiO 2 or pure Ge0 2 .
Inventors
- 👤 Kevin Christopher Byron
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 04:26
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/30; H01S3/302; H01S3/307
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
117 words
An optical amplifier-comprising a length of optical fibre (15); a semiconductor laser and drive means therefor (11), the output of the semiconductor laser comprising a pulsed pump signal (14); and coupler means (12) having an input for an optical signal (13), of a first wavelength, to be amplified, an input for the pump signal (14) and an output coupled to an input end of the optical fibre (15), and wherein in use the fibre (15) is optically pumped by the pump signal (14) at a second wavelength and gain is obtained at the first wavelength in the signal (13) to be amplified, which first wavelength corresponds to one ore more Stokes shift from the pump signal (14).
Claim 2
Dependent Claim
117 words
An optical amplifier-comprising a length of optical fibre (15); a semiconductor laser and drive means therefor (11), the output of the semiconductor laser comprising a pulsed pump signal (14); and coupler means (12) having an input for an optical signal (13), of a first wavelength, to be amplified, an input for the pump signal (14) and an output coupled to an input end of the optical fibre (15), and wherein in use the fibre (15) is optically pumped by the pump signal (14) at a second wavelength and gain is obtained at the first wavelength in the signal (13) to be amplified, which first wavelength corresponds to one ore more Stokes shift from the pump signal (14).
Claim 3
Dependent Claim
24 words
An optical amplifier as claimed in claim 1, characterised in that the optical fibre (15) has a high Raman cross-section and low transmission loss.
Claim 4
Dependent Claim
24 words
An optical amplifier as claimed in claim 1, characterised in that the optical fibre (15) comprises single mode GeO 2 doped Si0 2 fibre.
Claim 5
Dependent Claim
22 words
An optical amplifier as claimed in claim 1, characterised in that the optical fibre (15) is comprised of pure Ge0 2 .
Claim 6
Dependent Claim
39 words
An optical fibre amplifier as claimed in any one of the preceding claims, characterised in that the semiconductor laser is comprised by GaInAsP for use in the range 1.0 to 1.8 micron or lead salt for mid I.R. applications.
Claim 7
Independent Claim
81 words
A method of amplifying a first optical signal (13) of a first wavelength comprising the steps of generating a pulsed pump signal (14) at a second wavelength by means of a semiconductor laser (11), and synchronously coupling (12) the first optical signal and the pump signal into a length of optical fibre (15), the first wavelength corresponding.to one Stokes shift from the pump signal wavelength, Raman stimulated emission in the optical fibre serving to induce gain in the first optical signal.
Claim 8
Independent Claim
81 words
A method of amplifying a first optical signal (13) of a first wavelength comprising the steps of generating a pulsed pump signal (14) at a second wavelength by means of a semiconductor laser (11), and synchronously coupling (12) the first optical signal and the pump signal into a length of optical fibre (15), the first wavelength corresponding.to one Stokes shift from the pump signal wavelength, Raman stimulated emission in the optical fibre serving to induce gain in the first optical signal.
Claim 9
Dependent Claim
23 words
A method as claimed in claim 6, characterised in that the optical fibre (15) has a high Raman cross-section and low transmission loss.
Claim 10
Dependent Claim
31 words
A method as claimed in claim 6, characterised.in that the optical fibre (15) is comprised of undoped SiO 2 fibre, GeO 2 doped SiO 2 fibre or pure GeO 2 fibre.
Claim 11
Dependent Claim
18 words
A method as claimed in claim 6, characterised in that the semiconductor laser (11) is comprised by GaInAsP.
References Cited (Backward Citations)
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