Two topological devices

by Prof. Ling Lu (陆凌) (Institute of Physics, Chinese Academy of Sciences)

Wednesday 17 Dec 2025, 10:30 → 11:30 Asia/Shanghai

Tsung-Dao Lee Institute/N4F-N400 - meeting room (Tsung-Dao Lee Institute)

Host: Prof. Qingdong Jiang  

Venue: TDLI Meeting Room N400

Tencent Meeting link:   https://meeting.tencent.com/dm/eOBtT9HopmCC  

Meeting ID: 421657141, no password

 

Abstract:

Despite three Nobel prizes, topological physics has yet to find its device applications. In this talk, I will discuss our endeavors to invent two topological photonic devices that significantly outperform their commercial counterparts.

First, we propose a topological principle for isolators by leveraging the one-way edge states. We design and experimentally validate such a topological isolator, achieving isolation > 100 dB around 10 GHz. This record-high performance surpasses five commercial junction isolators connected in series --- mature devices developed since World War II. Given the ubiquity of microwave isolators in technologies from mobile base stations and radars to quantum computing, our work has the potential for broad impact.

Second, we show that the textbook design of everyday semiconductor lasers, used in internet communications and cellphones, aligns with standard topological models in 1D. By advancing to the 2D vortex zero mode, we invent the topological-cavity surface-emitting lasers (TCSELs). Finally, we demonstrate the monopole modes in 3D, completing the kink-vortex-monopole trilogy of topological defect modes.

 

References：

Nature Nanotechnology 15, 1012 (2020)

Nature Photonics 16, 279 (2022)

Nature Communications 15, 7327 (2024) 

Nature Photonics 19, 1064 (2025)

 

Biography:

Ling Lu is a group leader in the Institute of Physics, Chinese Academy of Sciences, Beijing China. He obtained his bachelor in Physics from Fudan University, and a Ph.D. in Electrical Engineering from University of Southern California where he worked on photonic crystal defect lasers. He was a postdoc at Massachusetts Institute of Technology, where he and colleagues coined “topological photonics” and discovered “Weyl points”. He was awarded the Chen Ning Yang Award by the Asian Pacific Societies, Pei Yuan Zhou Award by the Chinese Physics Society, and the Highly Cited Researchers by Clarivate Web of Science. His group is developing “hypergap” materials and two topological devices, the topological-cavity surface-emitting laser (TCSEL) and the topological microwave isolator.