Liquid crystal lasers: the last decade and the future

The demonstration of the first ruby laser in 1960 led to a revolution in science and technology. The lasers have significantly influenced the development of new approaches to spectroscopy, giving previously undreamed insights into physics, chemistry, and other scientific areas. The search for new materials for light amplification is one of the fundamental subjects of modern photonics and nanotechnology. In this review, we summarize the most appealing progress in developing liquid crystalline (LC) micro and nano-lasers during the last decade, together with their applications and description of perspectives for the future. We will describe the physical background necessary to understand the operation principles of LC lasers, including a description of radiative transition phenomena and LC matter. The article will be divided into separate sections concerning different approaches of LC lasers realization, including; band edge, DFB, DBR, VECSEL, and random cavities utilization. We will also discuss how the LC phases can influence the design of laser devices. Finally, the potential applications, perspectives, and conclusions will be discussed at the end of the article.