Resonant measurements of nonlinear lensing in a VECSEL gain sample

Adrian H. Quarterman, Conor J C Smyth, Shamil Mirkhanov, Keith G. Wilcox

Research output: Chapter in Book/Report/Conference proceedingConference contribution


In recent years there have been several reports describing self-modelocking (SML) in vertical-external-cavity surfaceemitting lasers (VECSELs). Some of these reports have suggested that the behaviour that has been observed results from nonlinear lensing in the VECSEL gain sample in a manner analogous to Kerr lens modelocking in solid state lasers. However to date none of the groups that have reported SML in VECSELs have performed measurements to ascertain whether nonlinear lensing occurs in the gain sample. Measurements of nonlinear lenses in VECSEL gain samples are therefore of value not only in order to understand the behaviour observed in the reports of SML, but also as a potentially crucial design tool for any mode-locked VECSEL, regardless of the modelocking method used. In a previous publication we described measurements which demonstrated that a defocusing nonlinear lens was present in an unpumped VECSEL gain sample, and that the inverse focal length of the lens increased with pump power, to the point of becoming a focusing lens for sufficiently high pump powers. Unfortunately, by necessity this measurement was performed using a probe laser which was not resonant with the quantum wells in the sample, meaning that the values measured may well be different from those experienced under operating conditions in a VECSEL. This paper describes a more complete characterisation of VECSEL gain sample nonlinear lensing with a probe laser whose wavelength is resonant with the gain sample quantum wells.

Original languageEnglish
Title of host publicationVertical External Cavity Surface Emitting Lasers (VECSELs) VI
EditorsKeith G. Wilcox
Place of PublicationSan Francisco
PublisherSPIE-International Society for Optical Engineering
ISBN (Electronic)9781628419696
Publication statusPublished - 10 Mar 2016
EventSPIE Photonics West 2016: Vertical External Cavity Surface Emitting Lasers (VECSELs) VI - The Moscone Center, San Francisco, United States
Duration: 15 Feb 201616 Feb 2016 (Link to Conference details)


ConferenceSPIE Photonics West 2016
Country/TerritoryUnited States
CitySan Francisco
Internet address


  • nonlinear lensing
  • semiconductor lasers

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics


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