Ultrafast Polariton Switch Realized by Institute of Physics Members

Performing long-distance communication using light is the standard way information is transmitted today, and is one of the key technologies underpinning the modern-day internet. A key component are optical switches, which are used to turn on and off the light that is being transmitted. The typical timescale for such switches is nanoseconds, or one billion switching events per second.

In a new paper entitled Optically Controlled Femtosecond Polariton Switch at Room Temperature, Professor Hui Li of ECNU, Institute members Professor Jian Wu, Professor Zheng Sun, Professor Tim Byrnes, and collaborators have experimentally realized a novel type of switch that works at timescales that are over 10,000 times faster than conventional switches. 

In this work, the team aimed to speed up optoelectronic switching by using a Bose-Einstein condensate of polaritons. Polaritons are a special type of particle that exists inside Zinc Oxide that are created when a laser illuminates the crystal. 

One of the benefits of using Zinc Oxide is that no cryogenic cooling is required, such that the experiment could be carried out at room temperature. By taking advantage of the unique properties of a Bose-Einstein condensate, the study found that its population could be very efficiently depleted in the hundred femtosecond timescales. 

The paper was published in one of the premier journals in physics Physical Review Letters and chosen as an Editor’s Suggestion.

Dedicated to providing platform for internal collaboration since establishment, the NYU-ECNU Institute of Physics at NYU Shanghai has helped to promote resource and knowledge sharing among its members by hosting academic events, launching internal grants, etc. The collaboration of our members also benefits scientific research productivity and facilitates innovation in frontier physics research around the globe.

Research image: All-optical terahertz (THz) switch based on a Bose-Einstein Condensate at room temperature. Image copyright to Professor Hui Li.
Group photo from right to left: Fei Chen (The 1st author of the paper), Hui Li, and Ziyu Ye. Institute members: Tim Byrnes, Jian Wu, Zheng Sun

Journal Reference:

Chen, Fei, Hui Li, Hang Zhou, Song Luo, Zheng Sun, Ziyu Ye, Fenghao Sun, Jiawei Wang, Yuanlin Zheng, Xianfeng Chen, Huailiang Xu, Hongxing Xu, Tim Byrnes, Zhanghai Chen and Jian Wu. "Optically controlled femtosecond polariton switch at room temperature." Physical Review Letters 129, no. 5 (2022): 057402.