Presentation Information
[8p-P07-6]Band-edge lasing from a re-filled cholesteric liquid crystal polymer template with 1D photonic crystal structure
〇Ja-Hon Lin, Hsuan-Li Huang1, Yu-Tong Yang1, Hsin-Yi Wei1, Chiung-Cheng Huang2 (1.Natl. Taipei Univ. of Tech., 2.Tatung Univ.)
Keywords:
band-edge lasing,cholesteric liquid crystal polymer film,photonic crystal bandgap
This work presents the successful demonstration of band-edge lasing from a freestanding dye-embedded nanoporous cholesteric liquid crystal polymer (DE-NPCLCP) film. The film was fabricated through a templating and infiltration process, where the nanoporous cholesteric liquid crystal polymer (NPCLCP) template was first produced by photopolymerizing a mixture of nematic monomer (RM257), chiral dopant (S811), nematic liquid crystal (E7), and a photoinitiator. After washing out the E7 to create a nanoporous structure, the film was immersed in a PM597 dye solution to form the DE-NPCLCP. The resulting freestanding film exhibited flexibility and good optical quality. Under excitation by a frequency-doubled Q-switched Nd:YAG laser (532 nm, 2.2 ns pulse duration), band-edge lasing was observed with a peak wavelength of ~629.4 nm. The lasing occurred at the short-wavelength edge of the photonic bandgap, attributed to a high density of optical states and zero group velocity. The measured lasing threshold was approximately 1.29 uJ/pulse. A conical-shaped emission pattern in the far field further confirmed the lasing behavior. This flexible lasing platform not only provides opportunities for lightweight and adaptable photonic devices but also offers the potential for tunable laser emission via mechanical deformation. Future work will explore the beam-steering properties of the DE-NPCLCP laser by applying mechanical stress, highlighting its promise for use in flexible optical sensors, wearable photonics, and adaptive light sources.