Second harmonic generation from nanocrystals under linearly and circularly polarized excitations
We study second harmonic generation (SHG) from non-centrosymmetric nanocrystals under linearly polarized (LP) and circularly polarized (CP) excitations. Theoretical models are developed for SHG from nanocrystals under both plane-wave and focused excitations. We find that the focused excitation reduces the polarization dependency of the SHG signal. We show that the SHG response under CP excitation is generally inferior to the average of LP excitations over all orientations. We verify the theory by measuring the SHG polar responses from BaTiO_3 nanocrystals with a scanning confocal microscope. The experimental data agrees well with the theory.
Additional Information© 2010 Optical Society of America. Received 26 Mar 2010; revised 10 May 2010; accepted 13 May 2010; published 21 May 2010. The authors thank Dr. Paul Bowen at EPFL for providing the BaTiO3 nanocrystals. This project is supported by the National Center of Competence in Research (NCCR), Quantum Photonics.
Published - Hsieh2010p10537Opt_Express.pdf