Liquid crystals (LCs), a state of matter that has properties between those of a conventional liquid and those of a solid crystal, are fast becoming a household name thanks to their widespread use in television, smartphone and computer displays. As such, research and development in the area of liquid crystal materials (LCMs) has also been rapidly progressing in recent years. To highlight breakthroughs in this area, the Optical Society (OSA) today published a special Focus Issue on LCMs for Photonic Applications ( in its open-access journal Optical Materials Express. The issue is organized and edited by Guest Editors Wei Lee of the Department of Physics and Center for Nanotechnology at the Chung Yuan Christian University in Taiwan, and Shin-Tson Wu of the College of Optics and Photonics at the University of Central Florida in Orlando.
"There is no doubt that the publication of this hot topic is timely," said Lee. "LCs have steadily been widening their commercial use over the past decade and the demand for more efficient technologies has been a boon to the research community."
The most common usage of LC technology is liquid crystal displays (LCDs), which are used in a wide range of applications including computer monitors, televisions, clocks and telephones, and have largely replaced cathode ray tube displays in new devices. In addition to flat panel displays, LCs are also used for other applications such as in thermometers, optical imaging, mechanical stress tests, and in the lasing medium.
Key Findings and Select Papers
The following papers are some of the highlights of the Optical Materials Express Focus Issue on LCMs for Photonic Applications. All are included in Volume 1, Issue 8 and can be accessed online at http://www.opticsinfobase.org/ome.
- With a convenient approach to reversible phototuning of the lasing frequency by means of UV irradiation, a novel tunable distributed-feedback laser based on a cholesteric liquid crystal composed of a mixture of cholesterol esters and azoxy nematics doped with a pyrromethene dye is demonstrated by Igor P. Ilchishin, Longin N. Lisetski, and Taras V. Mykytiuk of the Institute of Physics and the Institute for Scintillation Materials in the National Academy of Sciences of Ukraine. The resulting luminescence yield is dramatically high, leading to efficient lasing at the selective reflection band edge.
Paper: "Reversible phototuning of lasing frequency in dye doped cholesteric liquid crystal and ways to improve it," Optical Materials Express, Vol. 1, Issue 8, pp. 1484-1493 (2011).
- The field of polymer-stabilized blue-phase liquid crystals has become extremely important in recent years because this new class of materials exhibits some attractive features, such as submillisecond response time, no need for molecular alignment layers, and optically isotropic dark state. Therefore, blue phase is emerging as a leading candidate for next-generation liquid-crystal displays based on the electro-optical Kerr effect. Omitting the complicated theories, Jin Yan and Shin-Tson Wu from the College of Optics and Photonics, University of Central Florida, provide a concise, topical summary of the fundamentals, material preparations, and display applications of polymer-stabilized blue phases, which is very accessible to readers and most suitable to serve as a practical guide for those who are interested in entering this particular field of developing new liquid crystal technology.