Xiang , J , Varanytsia , A , Minkowski , F , Paterson , D A , Storey , J M D , Imrie , C T , Lavrentovich , O D & Palffy-Muhoray , P 2016 , ' Electrically tunable laser based on oblique heliconical cholesteric liquid crystal ' PNAS , vol. 113 , no. 46 , pp. 12925-12928 . DOI: 10.1073/pnas.1612212113