1. Condensation of exciton-polaritons at room temperature
Wei Xie, Liaoxin Sun, Hongxing Dong, Yanjing Ling, Jian Lu, Qiju Ren, Weihang Zhou, Xuechu Shen, Zhanghai Chen
Surface Physics Laboratory, Department of Physics, Fudan University, Shanghai , China
We report one dimensional exciton-polariton dispersion in ZnO whispering gallery-like micro-rod at room temperature through angle resolved fluorescence spectrometry. The experiment results agree well with the theoretical calculation based on coupled oscillators model. By increasing pump power, we observe the condensation of polariton at the ground state of k-space at the threshold. Moreover, when pump power further increases, the adjacent WG polariton mode with lower energy is remarkably populated by polariton-polariton scattering process.
Experiment and Discussion
(a)
(b)
(a) The cross section of ZnO rod.
Appropriate light forms WG mode.
(b) Collection photoluminescence
emitting from different angle.
(c) Angle resolved PL( samll angle )
and theoretical simulation.
Polariton-polariton scattering under different pump power. The power
increases from 350 nw to 1080 nw
with scattering effect more remarkably.
Condensation of exciton-polaritons at
room temperature when increasing
pump power to the threshold.
The dispersion of exciton-polariton :
Detection of the leakage photons with
two cross-linear polarizations. The
direction of TE polarization is
Experiment data can be fitted by bose
distribution relation.
Inset: Angle dependency of the PL
intensity after condensation.
Power dependency of the scattering
effect at angle 360.
Inset: Angle dependency of the PL intensity under three different pump powers.
perpendicular to the direction of K//.
Conclusion
We have observed one dimensional exciton-polariton dispersion and its condensation with increasing pump power to the threshold in ZnO WG-like micro-rod at RT. In addition, the polariton-polariton scattering process was found when further increasing pump power. Our work will contribute to the further research on polariton dynamics and the developing of novel polariton based devices.