Professor Xue-Chu Shen (沈学础 院士) Shanghai Institute of Technical Physics, Chinese Academy of Science Department of Physics, Fudan University

Abstract: The exciton polariton in 1D hexagonal nano ZnO wire has been investigated by use of micro-PL spectroscopy in both frequency and momentum spaces. The hexagonal structure of the wire form a 1D whispering gallery micro-cavity and the optical cavity mode can be coupled and hybridized with exciton excited by incident light, depending on the incident photon energy. The dispersion of the exciton polariton was obtained at first for different kinds of polariton composed of all three kinds of exciton hybridized with different branches of whispering gallery cavity mode by scanning the micro-PL along with a tapered wire. The experiment were extended into momentum space by use of the angle resolved micro-PL and FFT optics; the polariton lasing in the nano wire was observed in both frequency and momentum spaces. Interestingly the spectra in momentum space show that the polariton was condensed at zero k while the power density of excitation becomes higher and the lasing is happening. The parameter scattering and the propagation in the wire (as a wave guide!) of the polariton condensate were observed and investigated while the characteristics of the condensate (BEC at room temperature!??) is in strongly contradictory discussion.

About the Speaker: Xue-Chu Shen was born in Jiangsu Province in April 1938, he graduated from the Physics Department of Fudan University in 1958. Long after graduation, he had worked with Shanghai Institute of Technical Physics, Chinese Academy of Sciences. He was elected as a member of Chinese Academy of Sciences in 1995. Professor Shen transferred to the Physics Department of Fudan University in 2001, mainly engaged in the scientific research and teaching of solid spectra theory and experimental methods, and made a lot of important achievements. He put forward and first implemented light modulator resonance excitation spectrum, modulation absorption spectroscopy under high pressure, inter-band transitions and induced cyclotron resonance enhanced, all of which made it possible to observe and study some of the weak solid spectrum phenomena. He has also many other significant research findings. Due to his contributions in scientific research, he won twice the National Natural Science Award, and the first prize of the National Natural Science Award by Chinese Academy of Sciences twice, and many other awards. Prof. Shen has published more than 200 papers, and quite a lot of his results were widely quoted in specialized publications, handbooks and even textbooks at home and abroad. He has a monograph named "optical properties of semiconductors", and 2 books published in cooperation with others, 3 Collected Works of meetings.

Date&Time: January 18, 2013 (Friday), 15:00-16:00
Location: 606 Conference Room, No.3 Heqing Road, Haidian District