Circularly Polarized Luminescence Optical Waveguides Based on One‐Dimensional Hybrid Copper–Silver Bromide Crystal

Abstract Chiroptical waveguides, capable of generating and propagating circularly polarized light (CPL), hold significant promise for next‐generation optoelectronic devices. However, developing novel, efficient chiroptical waveguides remains challenging, due to the difficulty of integrating strong intrinsic chiroptical activity with efficient directional light transport within a single crystalline material. Here, we report a new enantiomeric pair of chiral hybrid metal halides, ( S/R ‐C 5 H 14 N 2 )CuAgBr 4 ( S/R ‐CuAg), featuring a one‐dimensional inorganic structure. Ag incorporation enhances photoluminescence quantum yield from 0.6% to 18.6%, while enabling bright CPL emissions with dissymmetry factors ( g lum ) of ± 7 × 10 −3 . The tightly packed inorganic lattice and highly anisotropic microstructure of S/R ‐CuAg exhibit a low optical loss coefficient of 9.6 × 10 −3 dB µm −1 . Crucially, microrod crystals of S/R ‐CuAg function as efficient chiroptical waveguides, simultaneously emitting and propagating CPL under unpolarized light excitation. This work establishes chiral hybrid metal halides as a viable platform for circularly polarized waveguide applications.