Change search
ReferencesLink to record
Permanent link

Direct link
Temporal coherence in mirrorless optical parametric oscillators
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: 0000-0003-2070-9167
Show others and affiliations
2012 (English)In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, Vol. 29, no 6, 1194-1202 p.Article in journal (Refereed) Published
Abstract [en]

One of the unique features of mirrorless optical parametric oscillators based on counterpropagating three-wave interactions is the narrow spectral width of the wave generated in the backward direction. In this work, we investigate experimentally and numerically the influence that a strong phase modulation in the pump has on the spectral bandwidths of the parametric waves and on the efficiency of the nonlinear interaction. The effects of group-velocity mismatch and group-velocity dispersion are elucidated. In particular, it is shown that the substantial increase in temporal coherence of the backward-generated wave can be obtained even for pumping with a temporally incoherent pump. A configuration of a mirrorless optical parametric oscillator is proposed where this gain in spectral coherence is maximized without a penalty in conversion efficiency by employing group-velocity matching of the pump and the forward-generated parametric wave.

Place, publisher, year, edition, pages
2012. Vol. 29, no 6, 1194-1202 p.
Keyword [en]
Counterpropagating, Group velocities, Group-velocity mismatch, Incoherent pump, Nonlinear interactions, Parametric waves, Spectral bandwidth, Spectral coherence, Spectral widths, Temporal coherence, Three-wave interactions, Unique features, Conversion efficiency, Phase modulation
National Category
Physical Sciences
URN: urn:nbn:se:kth:diva-92274DOI: 10.1364/JOSAB.29.001194ISI: 000305029900008ScopusID: 2-s2.0-84861809132OAI: diva2:513086
Swedish Research Council

QC 20120702

Available from: 2012-03-30 Created: 2012-03-30 Last updated: 2012-07-02Bibliographically approved
In thesis
1. Nonlinear response in engineered optical materials
Open this publication in new window or tab >>Nonlinear response in engineered optical materials
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Material and structure engineering are increasingly employed in active optical media,in this context defined as media capable of providing laser or/and optical parametric gain. For laser materials, the main aim of the engineering is to tailor the absorption and emission cross sections in order to optimise the laser performance. At the same time, the engineering also results in a collateral modification of the material’s nonlinear response. In the first part of this work, the nonlinear index of refraction is characterised for two crystallographic forms of laser-ion doped and undoped double-tungstate crystals. These laser crystals have broad gain bandwidths, in particular when doped with Yb3+. As shown in this work, the crystals also have large Kerr nonlinearities, where the values vary significantly for different chemical compositions of the crystals. The combination of a broad gain bandwidthand a high Kerr nonlinearity makes the laser-ion doped double tungstates excellent candidates to employ for the generation of ultrashort laser pulses by Kerr-lens modelocking. The second part of the work relates to the applications of engineered second-order nonlinear media, which here in particular are periodically-poled KTiOPO4 crystals. Periodic structure engineering of second-order nonlinear crystals on a submicrometre scale opens up for the realisation of novel nonlinear devices. By the use of quasi-phase matching in these structures, it is possible to efficiently downconvert a pump wave into two counterpropagating parametric waves, which leads to a device called a mirrorless optical parametric oscillator. The nonlinear response in these engineered submicrometre structures is such that the parametric wave that propagates in the opposite direction of the pump automatically has a narrow bandwidth, whereas the parametric wave that propagates with the pump essentially is a frequency-shifted replica of the pump wave. The unusual spectral properties andthe tunabilities of mirrorless optical parametric oscillators are investigated.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. xii, 98 p.
Trita-FYS, ISSN 0280-316X ; 2012:13
nonlinear optics, nonlinear index of refraction, double tungstates, periodic poling, KTiOPO4, quasi-phase matching, parametric down-conversion, mirrorless optical parametric oscillators
National Category
Atom and Molecular Physics and Optics
urn:nbn:se:kth:diva-92221 (URN)978-91-7501-295-7 (ISBN)
Public defence
2012-04-27, FD5, Albanova, Roslagstullsbacke 21, KTH, Stockholm, 10:00 (English)
QC 20120330Available from: 2012-03-30 Created: 2012-03-29 Last updated: 2012-03-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Strömqvist, GustavPasiskevicius, ValdasCanalias, Carlota
By organisation
Laser Physics
In the same journal
Journal of the Optical Society of America. B, Optical physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 68 hits
ReferencesLink to record
Permanent link

Direct link