Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Highly efficient temporally stable narrow linewidth cryogenically cooled Yb-fiber laser
KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.ORCID iD: 0000-0002-2508-391X
KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.ORCID iD: 0000-0001-7688-1367
2009 (English)In: Optics Express, ISSN 1094-4087, Vol. 17, no 10, 8433-8438 p.Article in journal (Refereed) Published
Abstract [en]

Cryogenic cooling is an effective way of increasing the efficiency in many solid-state lasers. In fiber lasers however, while the efficiency is increased, a reduced reabsorption in combination with reduced homogeneous broadening tends to broaden the linewidth, yielding a low spectral power density of the laser emission. In this work we lock a cryogenically-cooled Yb-doped fiber laser with a volume Bragg grating to overcome this problem and achieve a temporally stable narrow linewidth highly efficient laser. We extract 11.4-W of output power in spectral window of less than 0.4-nm with 14.5-W of launched pump light.

Place, publisher, year, edition, pages
2009. Vol. 17, no 10, 8433-8438 p.
National Category
Atom and Molecular Physics and Optics
Identifiers
URN: urn:nbn:se:kth:diva-11709DOI: 10.1364/OE.17.008433ISI: 000266381900075Scopus ID: 2-s2.0-66449133549OAI: oai:DiVA.org:kth-11709DiVA: diva2:279902
Note
QC 20100721Available from: 2009-12-07 Created: 2009-12-07 Last updated: 2015-03-30Bibliographically approved
In thesis
1. High Performance Fiber Lasers with Spectral, Thermal and Life Time Control
Open this publication in new window or tab >>High Performance Fiber Lasers with Spectral, Thermal and Life Time Control
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis contains the results of research in the fields of spectral control, efficiency andlifetime of high-power, rare-earth doped fiber lasers, properties which are of greatimportance for scientific and industrial applications. Volume Bragg gratings (VBGs) has forthe first time been used together with fiber lasers and the laser performance in terms ofspectral purity, thermal stability, and tunability was evaluated. It was found that VBGs arean excellent high-contrast spectral filter for many fiber laser designs where bulk optics arenecessary, or for speciality fibers such as photonic crystal fibers or large-mode area fibers. Itis also shown that they work equally well in low power and very high-power configurations,i.e. for fiber lasers ranging three orders of magnitude in output power, from ~100 mW to >100 W. Furthermore, VBGs are shown to work very well as tunable spectral filters,producing a narrow emission linewidth in a compact setup.

Concerning efficiency, it was shown how cryogenic cooling of the fiber gain-mediasubstantially increased the efficiency. The reasons are an increased pump absorption, anincreased gain cross-section, and a decreased threshold. The broad spectral output resultingfrom the low temperatures is shown to be easily mitigated by implementing a VBG as oneof the cavity mirrors. The low operating temperature is also shown to efficiently suppressself-pulsing in the fiber laser, which, if left unchecked, can lead to catastrophic break-downof the fiber end-faces. The increased absorption and suppressed self-pulsing allowed a fiberlength long enough to almost completely absorb the pump, which meant that, for the samepump power, more than 60 % higher output-power was attained.

Finally, the lifetime issue of Yb-doped fiber lasers was addressed. It was found that Cecodopingsubstantially reduced the photodarkening-rate while leaving other fiber parametersessentially unchanged. This is especially important for Yb-doped fiber lasers emitting at 980nm, as the high inversion required make them very susceptible to photodarkening. It wasshown that the output power in Yb-doped fiber lasers degraded quickly when no Cecodopingwas present and, conversely, with the right Yb/Ce-codoping ratio, degradationfreelasing could be achieved for many hours.

The research results obtained in this work could be of great interest to scientists andengineers working with spectroscopy, display systems, non-linear optics to just name a fewexamples.

Place, publisher, year, edition, pages
Stockholm: KTH, 2009. x, 72 p.
Series
Trita-FYS, ISSN 0280-316X ; 2009:65
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-11711 (URN)978-91-7415-504-4 (ISBN)
Public defence
2009-12-11, Sal FB52, AlbaNova, Roslagstullsbacken 21, Stockholm, 10:00 (English)
Opponent
Supervisors
Note
QC 20100721Available from: 2009-12-07 Created: 2009-12-07 Last updated: 2015-03-30Bibliographically approved
2. Compact solid-state lasers in the near-infrard and visible spectral range
Open this publication in new window or tab >>Compact solid-state lasers in the near-infrard and visible spectral range
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The subject of this thesis is the exploration of new concepts for compact solid-state lasers in the visible and near-infrared spectral range using new components such as volume Bragg gratings for wavelength stabilisation and wavelength tuning. Also single-walled carbon nanotubes for mode-locking and Q-switching of lasers have been studied.We have developed a new method for the tuning of solid-state lasers by replacing a dielectric mirror with a transversally chirped volume Bragg grating, which allows smooth wavelength tuning without additional elements inside the laser cavity. The result is a more compact laser, since the tuning mechanism and output coupler are incorporated in one component. Another benefit is an increased efficiency, since additional elements inside the cavity will always add to the total loss of the laser. This has been demonstrated for a broadband ytterbium laser around 1 µm and a single-longitudinal-mode Nd:YVO4 laser around 1.06 µm. A volume Bragg grating has also been used to construct an efficient, narrow-linewidth ytterbium fiber laser and the employment of a volume Bragg gratingas the pump mirror of a solid-state laser for frequency-doubling has been investigated. Both lasers represent a practical solution, eliminating the use of additional intracavity elements.

Second-harmonic generation is an efficient way to access the visible spectral range using diode-pumped solid-state lasers. However, these lasers can suffer from large amplitude fluctuations, which has been analyzed in more detail for an optically-pumped semiconductor disk-laser and a volume Bragg grating locked ytterbiumlaser. The control of those amplitude fluctuations is very important, since many applications like fluorescence microscopy require a laser with a constant output power and as little noise as possible.

In addition to this, we have demonstrated, that saturable absorbers based on quan-tum dots and carbon nanotubes can be used to mode-lock compact laser at a wavelength around 1.03 µm. Those lasers have many interesting applications incommunications, clock generation, metrology and life sciences.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. xii, 78, xi p.
Series
Trita-FYS, ISSN 0280-316X ; 2013:13
Keyword
volume Bragg gratings, single-longitudinal-mode laser, laser tuning, Q-switching, mode-locking, carbon nanotubes, semiconductor lasers, neodymium, ytterbium, nonlinear optics, KTP
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-121976 (URN)978-91-7501-764-8 (ISBN)
Public defence
2013-05-30, FD5, Albanova, Roslagstullsbacken 21, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20130507

Available from: 2013-05-07 Created: 2013-05-07 Last updated: 2015-03-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopushttp://www.opticsinfobase.org/abstract.cfm?URI=oe-17-10-8433

Authority records BETA

Pasiskevicius, ValdasLaurell, Fredrik

Search in DiVA

By author/editor
Jelger, PärSeger, KaiPasiskevicius, ValdasLaurell, Fredrik
By organisation
Laser Physics
In the same journal
Optics Express
Atom and Molecular Physics and Optics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 91 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf