Cardiff University, United Kingdom

Email: OhS2@cardiff.ac.uk

报告摘要:

To demonstrate topological lasers, several different schemes have been employed, for example, a ring resonator array [1] and photonic crystal slabs [2]. In those, a top-down approach, which requires e-beam pattering and chemical etching, has been successful in fabricating such ring resonator arrays or air-hole type photonic crystals. However, the top-down approach suffers from large side wall roughness and is limited in achieving a high aspect ratio. On the other hand, selective area heteroepitaxy of highly ordered III-V nanowires on silicon-on-insulator (SOI) substrate provides a unique bottom-up platform to integrate on-chip light sources with silicon photonics. In this presentation, I will present numerical/experimental results on 1D and 2D topological lasers made of InGaAs nanowire arrays grown on SOI wafer. The nanowire arrays, which are rod-type photonic crystals, are composed of nanowires arranged in 1D Su-Schrieffer-Heeger (SSH) lattice and 2D deformed honeycomb lattice, respectively. I will show the 1D SSH lattice lases with topological edge modes [3] and 2D lattice can have directional emission toward normal direction [4]. The nanowire platform is believed to be an excellent platform to demonstrate non-Hermitian topological photonics with spatially modulated pumping.  

References

1. M. A. Bandres, et al., Science, Vol. 359, p. eaar4005 (2018).

2. C. Han, M. Lee, S. Callard, C. Seassal, and H. Jeon, Light Sci. Appl., Vol. 8, p. 40 (2019).

3. Y. Gong, L. Guo, S. Wong, A. J. Bennett, and S. S. Oh, Sci. Rep., Vol. 11, p. 1055 (2021).

4. C. Messina, Y. Gong, O. Abouzaid, B.-P. Ratiu, T. Grieb, Z. Yan, A. Rosenauer, S. S. Oh, and Q. Li, Adv. Opt. Mater. Vol. 11, p. 2201809 (2023).

报告人简介: Sang Soon Oh received his PhD degree in Physics from Korea Advanced Institute of Science and Technology, South Korea. After a post-doctoral fellowship at Electronics Telecommunications Research Institute (ETRI) in South Korea (2007-2010), he joined the Department of Physics at University of Surrey, UK as a postdoc (2010). In 2011, he joined the Condensed Matter Theory group in the Department of Physics and Optical Semiconductor Device group in the Department of Electrical and Electronics Engineering at Imperial College London. Since December 2017, he has been Sêr Cymru II Rising Star fellow in the School of Physics and Astronomy in Cardiff University, United Kingdom.

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　　　　顾长志研究员（82648197）