Liquid crystal THz optics – An overview and recent advances

  • Ci-Ling Pan National Tsing Hua University
Keywords: THz, Liquid Crystals


Recently, the science and technology of sub-millimeter or terahertz (THz) waves have made progress by leaps and bounds. Applications in fields ranging from bio-medicine, 3D imaging, tomography, and characterization of materials have been demonstrated. Sub-THz radio-over- fiber communication at data rate exceeding 20 Gb/s over a 25 km fiber link was also demonstrated. To meet the demands of the exploding THz field, many novel quasi-optic components, such as phase shifter, phase grating, polarizers, and filters have been developed. In particular, a number of tunable THz devices employing liquid crystals (LCs) have attracted considerable attention. Partly, the unexpected large birefringence of liquid crystals and low attenuation in the THz frequency range is responsible for the realization of such advances.
In this talk, we provide an overview of the field liquid crystal THz optics and discuss recent advances in the field. After a brief introduction to THz technology, the optical properties of liquid crystals in the THz frequency range will be presented. This is followed by an overview of various THz optical components with liquid-crystal-enabled functionalities, e.g., phase shifters, polarizers, birefringent filters of Lyot and Solc types, phase grating and beam deflectors, and so on.

About the Speaker

Ci-Ling Pan is a Tsing Hua Chair Professor of Physics and Photonics, former Vice President for R&D, and the Director of the Operation Center for Industrial Collaboration, National Tsing Hua University (NTHU), Hsinchu, Taiwan. He taught at the National Chiao Tung University (NCTU) (1981-2009) and held visiting professorships at Osaka University (2004) and Chinese University of Hong Kong (CUHK) (2008), previously. Prof. Pan's fields of study fall mainly in laser science and engineering as well as photonics. Recent research highlights include pioneering the field of liquid crystal THz photonics, femtosecond-laser recrystallization and  activation  of  silicon  for  TFT  as  well  as  novel  THz  generators  and detectors. The latter were used in diverse applications such as diagnostics of technologically important materials for photovoltaics, assessing burn trauma and optical-network-compatible W-band (100 GHz or 0.1 THz) wireless communication Link at a data rate beyond 20 Gbit/s. Prof. Pan is a Fellow of APS, IEEE, OSA and SPIE, an Academian of the Asia-Pacific Academy of Materials. He is a Traveling Lecturer of OSA (2008 to date), a Distinguished Lecturer of the IEEE Electron Device Society (2015 to date), a member of Commission C17 (Quantum Electronics) of IUPAP (2011-2014) and Commission D (Electronics and Photonics) of URSI (2013 to date). Prof. Pan has currently published more than 250 refereed journal articles and he also holds 20 Taiwan patents and 13 US patents. A full list of publications is available on his faculty webpage. According to Google Scholar, his publications were cited 5776 times with an h-index of 30 and i10-index of 129 (as of March 2017).