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Generation and modulation of optical vortices

with liquid crystal technology

 Prof. Yan-qing Lu

College of Engineering and Applied Sciences, Nanjing University, China

Friday, August 22, 2014 / 11:00am-12:00pm@ CREOL  102

Abstract:

We present a technique for producing tunable optical vortices and other structured wavefronts by using liquid crystal (LC) photo-patterning technology. To write patterned alignment structures in to LC cells, a home-made micro-lithography system with a digital micro-mirror device (DMD) as dynamic mask forms arbitrary micro-images on photo-alignment layers and further guides the LC molecule orientations. Arbitrary fine photo-patterning fork gratings, polarization fork gratings, q-plates are fabricated. The related wavefront transformation properties are studied. Clear optical vortices with designed topological charges are obtained in different wavelengths. When a voltage is applied on the cell, index re-distribution is induced due to the realignment of LC molecules; and then the optical vortices become tunable. In addition, some recent results on LC tunable Airy beams, vector beams are also introduced.

 

Biography:

Prof. Yan-qing Lu received both his BS and Ph.D. degrees from Nanjing University, China, in 1991 and 1996 respectively. He has five-year experiences in US and China telecomm industries. He designed and developed a serial of liquid crystal based fiber-optic devices with his colleagues, which include variable optical attenuators, variable Mux/Demux, DWDM wavelength blocker etc. He is currently a Professor at the College of Engineering and Applied Sciences, Nanjing University. His research interests include liquid crystal photonics, nonlinear optics and fiber optics. He is the author or co-author of ~130 peer-reviewed papers with over 1600 ISI citations. He also holds more than 40 domestic or international patents or pending patents. He currently serves as a deputy editor of Optical Materials Express. He was a visiting research scientist in Prof. S. T. Wu’s group in CREOL from 2003 to 2005.

 

For more information:

SID UCF Student Branch Chair: Fenglin Peng, fenglin@knights.ucf.edu

SID UCF Student chapter advisor: Prof. Shin-Tson Wu, swu@mail.ucf.edu

IEEE Photonics Society Chair: Ruidong Zhu, ruidong.zhu@knights.ucf.edu