Mismatching in Meso-/Microscopic Orientation Drives Optical Anisotropy to Unlock Multicolor Nonreciprocal Circularly Polarized Luminescence in Chiral Polymer Elastomeric Films
Thin films with nonreciprocal circularly polarized luminescence (CPL) emit circularly polarized light with opposite handedness from its two opposite sides, holding great promise for advancing optical multiplexing technologies. Herein, we introduce component orientation mismatch into chiral composite films via stretching, which leads to macroscopic optical anisotropy and accordingly drives the films to show nonreciprocal CPL activity. Stretching triggers linear dichroism-linear birefringence (LD-LB) coupling to realize nonreciprocal circular dichroism (CD) in elastomer films consisting of thermoplastic polyurethane (TPU) and chiral polyacetylene (R/S-PSA). Moreover, fluorescence anisotropy-linear birefringence (f-LB) coupling occurs after introducing fluorescent groups into the films to achieve multi-color nonreciprocal CPL. The unstretched films exhibit reciprocal CPL with a luminescence dissymmetry factor (|glum|) of 10⁻¹, with handedness determined by PSA’s intrinsic helical chirality. In the stretched films, the oriented fluorescent groups undergo f-LB coupling with matrix crystallization, resulting in nonreciprocal CPL (|glum|=10⁻²). Based on this distinctive chiroptical feature, we have developed chiral logic gates, multidimensional optical encryption systems, and enantioselective photopolymerization platforms to demonstrate the potential uses of the as-obtained CPL films. This work provides both fundamental insights into and a versatile material platform for developing smart nonreciprocal photonic systems with advanced chiroptical functionality.