A virtual all-optical tunable terahertz Fresnel zone plate is achieved utilizing the localized distribution of the transient electron plasma on a silicon wafer. Its focusing and imaging performance are experimentally demonstrated. Experimental results show that the effect of the virtual zone plate is the same as an actual one. Adjusting the spatial pattern of the electron plasma, the central wavelength and the focal length of the virtual zone plate can be all-optically dynamically steered. The research is a significant step to the development of tunable optical imaging elements.
© 2013 Optical Society of America
Original Manuscript: August 14, 2013
Revised Manuscript: October 8, 2013
Manuscript Accepted: October 8, 2013
Published: November 12, 2013
Xinke Wang, Zhenwei Xie, Wenfeng Sun, Shengfei Feng, Ye Cui, Jiasheng Ye, and Yan Zhang, "Focusing and imaging of a virtual all-optical tunable terahertz Fresnel zone plate," Opt. Lett. 38, 4731-4734 (2013)