Flexible Acid‐Responsive Polymeric Phosphorescent Microfibers for Tunable Optical Waveguide

Abstract Phosphorescence optical waveguides, flexible ones in particular, are fascinating on account of their fundamental and practical values in photonics and optoelectronics devices. However, the majority of optical waveguides reported so far are fluorescent waveguides, the phosphorescent waveguides, especially ones with both flexibility and stimulus‐response are rarely studied. Herein, one‐dimensional phosphorescent microfibers are developed by employing the flexible polymer as the matrix and the phosphorescent emitter as the transducer for out‐coupled light, and their phosphorescent waveguide attributes are studied in detail. Significantly, benefiting from the non‐covalent clipping of molecular tweezer for Pt(II) triplet emitter, the strong and robust tip emission could be obtained for phosphorescent waveguiding microfiber. Furthermore, the asymmetric propagation of phosphorescent waveguide could be achieved via partly acid treatment, since acid could trigger the guest release accompanied by the emission decline. More interestingly, the phosphorescent microfiber exhibits flexible optical waveguide feature and reversible switching of tip emission. Based on the above, Boolean logic operation is selected to demonstrate the application of tunable tip emission. This study establishes an effective and convenient strategy to realize flexible phosphorescent waveguide with tunable tip emission, which is of fundamental value for designing optical functional elements and manufacturing intelligent flexible photonic devices with promising application potential.