Beyond plasmonics: oxide and semiconductor nanomaterials for enhancing nonlinear optical signals
Event details
Date | 24.04.2017 |
Hour | 13:15 › 14:15 |
Speaker | Prof. Rachel Grange, EPFZ |
Location | |
Category | Conferences - Seminars |
Nonlinear optical processes are known to be weak in bulk materials and extremely small at the nanoscale since they mainly scale with the volume. Here I will show several strategies to maximize nonlinear optical signals in nano-oxides with Perovskite crystalline structure and in III-V nanowires. First, I will demonstrate how we enhance second-harmonic generation (SHG) by using the scattering properties of individual barium titanate (BaTiO3) nanoparticles. We use the Mie resonances to achieve an SHG enhancement of four orders of magnitude within the same nanoparticle1. Our results suggest that a strong increase of the SHG signal can be obtained without using plasmonic or hybrid nanostructures.
Besides chemically synthesized nanostructures, we developed lithography processes to obtain high aspect ratio lithium niobate (LiNbO3) nanowaveguides. We demonstrate phase-matching and use it to increase the guided SHG power by a factor of more than 40. We also increase non-phase-matched guided second-harmonic by engineering the nanowire length2,3. Those bright nanostructures can serve for developing compact efficient nonlinear optical sources or waveguides. Finally I will report on cavity effects in GaAs nanowires and on a powerful multiphoton imaging method to distinguish various crystal structures in individual nanowires4.
References
(1) Timpu, F.; Sergeyev, A.; Hendricks, N. R.; Grange, R. Second-Harmonic Enhancement with Mie Resonances in Perovskite Nanoparticles. ACS Photonics 2017, 4, 76–84.
(2) Sergeyev, A.; Geiss, R.; Solntsev, A. S.; Sukhorukov, A. A.; Schrempel, F.; Pertsch, T.; Grange, R. Enhancing Guided Second-Harmonic Light in Lithium Niobate Nanowires. ACS Photonics 2015, 2, 687–691.
(3) Sergeyev, A.; Reig Escalé, M.; Grange, R. Generation and Tunable Enhancement of Sum-Frequency Signal in Lithium Niobate Nanowires. J. Phys. D Appl. Phys 2017, 50.
(4) Timofeeva, M.; Bouravleuv, A.; Cirlin, G.; Shtrom, I.; Soshnikov, I.; Reig Escalé, M.; Sergeyev, A.; Grange, R. Polar Second-Harmonic Imaging to Resolve Pure and Mixed Crystal Phases along GaAs Nanowires. Nano Lett. 2016, 16, 6290–6297.
Bio:
Rachel Grange graduated in Physics at EPFL in 2002 and obtained her PhD in ultrafast laser physics at ETH Zurich in 2006. During her post-doc with D. Psaltis, she worked on nonlinear bioimaging with Perovskite nanoparticles. From 2011 to 2014, she was group leader at the Friedrich Schiller University in Jena Germany. Since January 2015, she is assistant professor at the Department of Physics at ETH Zurich. Her laboratory investigates the optical behavior of nanomaterials for developing applications in optoelectronics or imaging. In 2016, she received an ERC starting grant to work on strategies to enhance optical nonlinearities in oxide nanomaterials.
Besides chemically synthesized nanostructures, we developed lithography processes to obtain high aspect ratio lithium niobate (LiNbO3) nanowaveguides. We demonstrate phase-matching and use it to increase the guided SHG power by a factor of more than 40. We also increase non-phase-matched guided second-harmonic by engineering the nanowire length2,3. Those bright nanostructures can serve for developing compact efficient nonlinear optical sources or waveguides. Finally I will report on cavity effects in GaAs nanowires and on a powerful multiphoton imaging method to distinguish various crystal structures in individual nanowires4.
References
(1) Timpu, F.; Sergeyev, A.; Hendricks, N. R.; Grange, R. Second-Harmonic Enhancement with Mie Resonances in Perovskite Nanoparticles. ACS Photonics 2017, 4, 76–84.
(2) Sergeyev, A.; Geiss, R.; Solntsev, A. S.; Sukhorukov, A. A.; Schrempel, F.; Pertsch, T.; Grange, R. Enhancing Guided Second-Harmonic Light in Lithium Niobate Nanowires. ACS Photonics 2015, 2, 687–691.
(3) Sergeyev, A.; Reig Escalé, M.; Grange, R. Generation and Tunable Enhancement of Sum-Frequency Signal in Lithium Niobate Nanowires. J. Phys. D Appl. Phys 2017, 50.
(4) Timofeeva, M.; Bouravleuv, A.; Cirlin, G.; Shtrom, I.; Soshnikov, I.; Reig Escalé, M.; Sergeyev, A.; Grange, R. Polar Second-Harmonic Imaging to Resolve Pure and Mixed Crystal Phases along GaAs Nanowires. Nano Lett. 2016, 16, 6290–6297.
Bio:
Rachel Grange graduated in Physics at EPFL in 2002 and obtained her PhD in ultrafast laser physics at ETH Zurich in 2006. During her post-doc with D. Psaltis, she worked on nonlinear bioimaging with Perovskite nanoparticles. From 2011 to 2014, she was group leader at the Friedrich Schiller University in Jena Germany. Since January 2015, she is assistant professor at the Department of Physics at ETH Zurich. Her laboratory investigates the optical behavior of nanomaterials for developing applications in optoelectronics or imaging. In 2016, she received an ERC starting grant to work on strategies to enhance optical nonlinearities in oxide nanomaterials.
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Practical information
- General public
- Free
Organizer
- Michele Ceriotti & Esther Amstad
Contact
- Michele Ceriotti & Esther Amstad