Flexibility and bending loss of waveguiding molecular fibers self-assembled from thiacyanine dye

The flexibility and waveguiding properties of fiber-shaped aggregates self-assembled from thiacyanine dye molecules in solution were investigated. Sharply bent fibers were prepared by drop-casting a solution containing the fibers on a glass substrate and immediately soaking up the solution. It was found that the fibers could be smoothly bent down to a radius of curvature R ≈ 2 μm. Fluorescence microscopy revealed that the fibers guide their fluorescence along such sharp bends. The bending losses were quantitatively measured using laser scanning optical microscopy.