Recent advances in lasing phenomena in cholesteric liquid crystals: materials, mechanisms and applications

Cholesteric liquid crystal (ChLC) lasers are emerging as tunable, low-threshold light sources that leverage the unique helical structure of cholesteric phases to enable distributed feedback and polarization control. This review examines recent developments in ChLC laser technology, covering fundamental concepts, practical applications, and emerging challenges. Key innovations, such as collective chirality-enhanced lasing, terahertz lasers, and up-conversion lasers, have significantly advanced the understanding of the intricate relationship between chirality and laser dynamics. The development of chirality modulation and cholesteric pitch control has opened new avenues for biomedical diagnostics and optical communications, enhancing diagnostic speed, image resolution, and signal transmission. The review also addresses persistent challenges, including limitations in theoretical modeling, scalability in fabrication, and material stability. Finally, it highlights emerging characterization techniques that promise solutions to these challenges, paving the way for the wider integration of ChLC lasers across diverse applications.