9-13 July 2012
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=11&confId=14"><font color=#ff0000>SAIP2012 PROCEEDINGS AVAILABLE</font></a>

Investigation of the time-dependent electric field induced second harmonic signal from the Si/SiO<sub>2</sub> interface

10 Jul 2012, 15:10
20m
Oral Presentation Track C - Photonics Photonics

Speaker

Mr Wilfrid Ndebeka (Laser Research Institute, Physics Department, University of Stellenbosch)

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD)?

PhD

Apply to be<br> consider for a student <br> &nbsp; award (Yes / No)?

Yes

Abstract content <br> &nbsp; (Max 300 words)

It has been observed that the second harmonic (SH) signal generated at the Si/SiO2 interface varies on a time scale of several seconds when illuminated with high intensity near infrared laser pulses (λ=800 nm, 75 ± 5 fs pulses, 80 MHz repetition rate, Epulse ≤ 10 nJ). The temporal behaviour arises from the generation of trap sites and subsequent trapping of charges at the interface via multi-photon processes. These trapped charges create an interfacial electric field which influences the nonlinear properties of the Si/SiO2 interface and leads to a time dependent second harmonic signal on continuous irradiation. This is known as electric field induced second harmonic (EFISH) generation. Initial experiments confirming some of these earlier results from our laboratory will be presented as well as the experimental setup for our future planned experiments. These future measurements will focus on the simultaneous measurement of the EFISH signal from a free standing oxidized Si membrane both in reflection and transmission as a function of incident polarization orientation and angle.

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Main supervisor (name and email)<br>and his / her institution

Erich Rohwer (egr@sun.ac.za)
Laser Research Institute, Physics Department, University of Stellenbosch

Primary author

Mr Wilfrid Ndebeka (Laser Research Institute, Physics Department, University of Stellenbosch)

Co-authors

Dr Christine Steenkamp (Laser Research Institute, Physics Department, University of Stellenbosch) Prof. Erich Rohwer (Laser Research Institute, Physics Department, University of Stellenbosch) Prof. Herbert Stafast (Institute of Photonic Technology (IPHT), Jena, Germany) Dr Pieter Neethling (Laser Research Institute, Physics Department, University of Stellenbosch)

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