Cholesteric liquid crystals (CLCs) doped with dyes have been shown to enable tunable coherent emission, thus forming the basis for versatile liquid crystal (LC)-lasers. However, their practical adoption is hindered by high pumping thresholds and limited long-term stability. This paper proposes a synergistic strategy to overcome these limitations by engineering the alignment layer and the CLC-host. A novel alignment layer based on polyvinylidene-fluoride (PVDF) incorporating NiO nanoparticles (NPs) has been developed. Electro-optical analysis revealed that an 8 wt% NiO NPs-PVDF alignment layer paired with a ZnO-coated slide facilitated highly efficient dipole redistribution, leading to faster switching and a significantly reduced threshold voltage. The integration of the optimized alignment layer with a 0.1wt% gold nanorods (Au NRs) blending CLC-host has enabled the successful fabrication of an advanced LC-laser. The helical assembly of plasmonic Au NRs has been demonstrated to enhance the localized optical field under pumping conditions, thereby achieving a 197% enhancement in DCM emission efficiency. Furthermore, the helical assemblies have been shown to result in a substantial improvement in thermal-dependent quenching of 9.35%. This synergistic approach, which combines a functionalized alignment layer with a plasmonic CLC-host, represents a significant advancement in the development of practical, low-threshold, and highly stable LC-lasers.

Liquid crystals (LCs) have been widely employed in laser applications, with their performance often enhanced through the incorporation of nanomaterials. In this study, we investigated cholesteric liquid crystals (CLCs) exhibiting a UV-tunable photonic bandgap (PBG), and demonstrated a notable enhancement in the emission of the embedded luminescent dye (4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM)) by progressively red-shifting the PBG. When confined within hollow nanocages, the CLCs exhibited a substantial nano-confinement effect, particularly under UV irradiation. Accordingly, Au-nanocages (Au-NCs) were incorporated into the CLCs. The resulting hybrids exhibited the PBG characteristics of the pristine CLCs, while displaying a substantially broadened reflection diagram and an accelerated rate of PBG shifting. Moreover, the gold-nanocages (Au-NCs) blending CLCs-hosts required significantly lower pumping energy to excite the DCM dye compared to pure CLCs. It also enabled an augmentation of the tunable emission intensity subjected to PBG modulation. With the incorporation of 0.10 wt.% Au-NCs, the threshold pumping energy of DCM in such hybrid was reduced to 0.432 µJ/pulse, corresponding to a 4.63% decrease, while the tunable range of emission intensity was expanded by 16.02%. Additionally, the DCM emission demonstrated improved long-term stability over an eight-week period, thereby substantiating the viability of such hybrids for the fabrication of high-performance LC-lasers.