Thermal control band-edge lasing toward near IR from dye-doped cholesteric liquid crystal: Relatively stable operation at high temperatures

Abstract

The exceptional band-edge lasing from dye-doped cholesteric liquid crystals (DD-CLCs), which can be easily fabricated by blending chiral molecules with nematic liquid crystals, showcases versatile tuning possibilities. In this work, we employed (ISO-(6OBA)2) with high helical twisting power (HTP) as the chiral molecule in the fabrication of DD-CLCs, ensuring superior tuning possibilities and operational stability at high temperatures. By thermally controlling DD-CLCs with a 5 wt% chiral molecule, the band-edge lasing peak exhibited a noticeable red shift with increasing temperature, demonstrating a tuning range of 106 nm as the temperature rose from 20 to 90 °C. In operation at 78 °C, the longest lasing peak of 692.7 nm was achieved from DD-CLCs with 4 wt% ISO-(6OBA)2. Furthermore, the long-term stability of band-edge lasing from DD-CLCs was proven during a three-hour monitoring period at a high operating temperature above 50 °C.