BEGIN:VCALENDAR VERSION:2.0 PRODID:www.dresden-science-calendar.de METHOD:PUBLISH CALSCALE:GREGORIAN X-MICROSOFT-CALSCALE:GREGORIAN X-WR-TIMEZONE:Europe/Berlin BEGIN:VTIMEZONE TZID:Europe/Berlin X-LIC-LOCATION:Europe/Berlin BEGIN:DAYLIGHT TZNAME:CEST TZOFFSETFROM:+0100 TZOFFSETTO:+0200 DTSTART:19810329T030000 RRULE:FREQ=YEARLY;INTERVAL=1;BYMONTH=3;BYDAY=-1SU END:DAYLIGHT BEGIN:STANDARD TZNAME:CET TZOFFSETFROM:+0200 TZOFFSETTO:+0100 DTSTART:19961027T030000 RRULE:FREQ=YEARLY;INTERVAL=1;BYMONTH=10;BYDAY=-1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:DSC-19774 DTSTART;TZID=Europe/Berlin:20230411T145000 SEQUENCE:1681191475 TRANSP:OPAQUE DTEND;TZID=Europe/Berlin:20230411T162000 URL:https://www.dresden-science-calendar.de/calendar/en/detail/19774 LOCATION:TUD\, SUMMARY:Physics Colloquium / Dr. Michael Rüsing: Towards Quantitative nonl inear microscopy at the nanoscale CLASS:PUBLIC DESCRIPTION:Speaker: \nInstitute of Speaker: \nTopics:\nWillkommen\n Locati on:\n Name: TUD ()\n Street: \n City: \n Phone: \n Fax: \nDescript ion:

Event announcement as pdf-Download (https://tu-dresden.de/mn/phys ik/ressourcen/dateien/physikalisches-kolloquium/2023-04-11-Phys_Kolloq-Rue sing-SoSe2023.pdf).

Abstract: 

Nonlinear optical (NLO) microscopy is widely employed for spatial analysis in mater ial science. A key feature of NLO processes is that they do not rely on pr obing energy transitions\, but rather just depend on the local symmetry an d crystallographic structure. This makes NLO methods very attractive\, as they do not require any special sample preparation and can provide intrica te insight into many properties. The signal generation in NLO microscopy l argely depends on the phase matching between the interacting beams\, which itself depends on material properties\, such as the dispersion of the ref ractive indices\, or the focusing of the light. As NLO are very sensitive to small changes\, small variations in focusing\, thickness\, refractive i ndex or wavelength can result in huge signal changes limiting the capabili ty for quantitative analysis\, if not accurately accounted for. In this wo rk\, I will show how all these effects can be dealt with theoretically by developing numerical\, as well as semi-analytical models allowing to descr ibe experiments with high accuracy. To demonstrate and test the capabiliti es of the modeling approaches\, experiments are performed on ferroelectric domain structures in lithium niobate. Here\, for example\, in periodicall y poled thin films\, the experiments show that quantitative analysis allow s to extract information way below the diffraction limit due to the cohere nt nature of a NLO process. The joint experimental and theoretical approac h represent a powerful tool for the interpretation and analysis of NLO exp eriments guiding the way to new techniques\, such as Coherent Anti-Stokes Raman (CARS) spectroscopy.

Short bio: Dr. Michae l Rüsing received his PhD in 2018 from the University of Paderborn on sp ectroscopy in ferroelectric materials. From 2018-2019 he was a postdoctora l researcher at the University of California\, San Diego\, where he worked on integrated\, nonlinear photonics in silicon. Since 2019\, he leads a r esearch team at the IAP under the supervision of Prof. Eng on ferroelectri c materials.

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