US5422897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-stage mono-mode optical fibre laser
Assignee: IPG Photonics Corp
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Filing: 1994-05-13
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Granted: 1995-06-06
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Expires: 2014-05-13
Abstract
Abstract A high power monomode laser arrangement is able to manipulate the output from a high power laser diode array pump source 3 using a computer-generated hologram 4 to launch a high proportion of the pump source light into a multimode fiber portion including in input reflector 6. A monomode fiber portion 2 with the same fundamental-mode spot size as the multimode fiber portion 1 is optically coupled to the multimode fiber portion and includes a reflector 5 which reflects only the fundamental mode of the multimode and monomode fiber portions. The fundamental mode reflection forced by the monomode fiber portion 2 provides the feedback necessary to force predominantly fundamental mode oscillation which enables stimulated emission in only the fundamental mode.
Inventors
- 👤 Richard Wyatt
- 👤 Jonathan R. Armitage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:27
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/0675; H01S3/07; H01S3/09; H01S3/091; H01S3/094; H01S3/094069; H01S3/094092
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
102 words
A laser comprising: an optical source to provide a pump signal at a wavelength of λ 1 ; a first waveguide portion which when optically pumped at a wavelength λ 1 is capable of laser action with an emission at wavelength λ 2 , the first waveguide portion exhibiting multimode behaviour at λ 2 ; a second waveguide portion which exhibits substantially single mode behaviour at λ 2 , the first and second waveguide portions being optically coupled together; and an optical cavity, the optical cavity being defined by first and second feedback means and including the first and second waveguide portions.
Claim 2
Dependent Claim
102 words
A laser comprising: an optical source to provide a pump signal at a wavelength of λ 1 ; a first waveguide portion which when optically pumped at a wavelength λ 1 is capable of laser action with an emission at wavelength λ 2 , the first waveguide portion exhibiting multimode behaviour at λ 2 ; a second waveguide portion which exhibits substantially single mode behaviour at λ 2 , the first and second waveguide portions being optically coupled together; and an optical cavity, the optical cavity being defined by first and second feedback means and including the first and second waveguide portions.
Claim 3
Dependent Claim
17 words
A laser according to claim 1 in which the first and second waveguide portions comprise optical fibres.
Claim 4
Dependent Claim
30 words
A laser according to claim 2 in which the second feedback means is a wavelength selective optical grating, which is written into the refractive index of the second optical fibre.
Claim 5
Dependent Claim
45 words
A laser according to claim 2 in which the first feedback means is an optical grating which is written into the refractive index of the first optical fibre, the grating being highly transmitting at wavelength λ 1 and highly reflecting at wavelength λ 2 .
Claim 6
Dependent Claim
25 words
A laser according to claim 1 further comprising a coupling means to couple the pump signal from the optical source into the first waveguide portion.
Claim 7
Dependent Claim
15 words
A laser according to claim 5 in which the coupling means a computer generated hologram.
Claim 8
Dependent Claim
41 words
A laser according to claim 1 wherein the fundamental mode spot size of the first waveguide portion at wavelength λ 2 is substantially the same as the fundamental mode spot size of the second waveguide portion at wavelength λ 2 .
Claim 9
Dependent Claim
30 words
A laser according to claim 1 wherein substantially only the fundamental mode of the first waveguide portion couples into the second waveguide portion at a wavelength of λ 2 .
Claim 10
Dependent Claim
14 words
A laser according to claim 1, in which the second waveguide portion comprises silica.
Claim 11
Dependent Claim
16 words
A laser according to claim 9 in which the second waveguide portion is doped with germania.
Claim 12
Dependent Claim
13 words
A laser according to claim 1, which the first waveguide portion comprises silica.
Claim 13
Dependent Claim
18 words
A laser according to claim 11 in which the first waveguide portion is co-doped with alumina and germania.
Claim 14
Dependent Claim
23 words
A laser according to claim 1 wherein the optical source is a diode array with an output power of at least 1 watt.
Claim 15
Dependent Claim
128 words
An up-conversion fibre laser which exhibits laser action at a second wavelength when pumped at a first wavelength substantially longer than the second wavelength, said laser comprising: an optical source to provide a pump signal at the first wavelength; a first fibre waveguide portion which when optically pumped at the first wavelength is capable of laser action with an emission at the second wavelength, the first fibre waveguide portion exhibiting monomode behaviour at the first wavelength and multimode behaviour at the second wavelength; a second fibre waveguide portion which exhibits substantially monomode behaviour at the second wavelength, the first and second fibre waveguide portions being optically coupled together; and an optical cavity, the optical cavity being defined by feedback means and including the first and second waveguide portions.
Claim 16
Dependent Claim
128 words
An up-conversion fibre laser which exhibits laser action at a second wavelength when pumped at a first wavelength substantially longer than the second wavelength, said laser comprising: an optical source to provide a pump signal at the first wavelength; a first fibre waveguide portion which when optically pumped at the first wavelength is capable of laser action with an emission at the second wavelength, the first fibre waveguide portion exhibiting monomode behaviour at the first wavelength and multimode behaviour at the second wavelength; a second fibre waveguide portion which exhibits substantially monomode behaviour at the second wavelength, the first and second fibre waveguide portions being optically coupled together; and an optical cavity, the optical cavity being defined by feedback means and including the first and second waveguide portions.
Claim 17
Dependent Claim
26 words
An up-conversion laser according to claim 14 which produces a laser output at the first wavelength which is in the blue region of the visible spectrum.
Claim 18
Dependent Claim
23 words
An up-conversion laser according to claim 15 in which the first fibre waveguide portion comprises a fluoride host and is doped with thulium.
Claim 19
Dependent Claim
119 words
An up-conversion laser according to claim 14 in which the optical source providing a pump signal comprises a laser including: an optical source to provide a pump signal at a wavelength of λ 1 ; a first waveguide portion which when optically pumped at a wavelength λ 1 is capable of laser action with an emission at wavelength λ 2 , the first waveguide portion exhibiting multimode behaviour at λ 2 ; a second waveguide portion which exhibits substantially single mode behaviour at λ 2 , the first and second waveguide portions being optically coupled together; and an optical cavity, the optical cavity being defined by first and second feedback means and including the first and second waveguide portions.
Claim 20
Dependent Claim
22 words
An up-conversion laser according to claim 17 in which the first waveguide portion of the pump contains neodymium as a laser dopant.
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) | 1998-06-05 | 1998-12-05 | 1999-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-05 | 2002-12-05 | 2003-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-05 | 2006-12-05 | 2007-06-06 | $7700.00 | Window Closed / Lapsed |