Circularly polarized luminescence optical waveguides in stretchable photonic crystal fibers for advanced human motion monitoring.

Flexible optical waveguides are vital for next-generation optoelectronics, yet conventional organic soft waveguides lack the dynamic, real-time modulation required for wearable systems. Here, we report mechanically programmable chiroptical waveguides utilizing stretchable photonic crystal (SPC) fibers. By establishing a rigorous quantitative framework relating helical pitch evolution to circularly polarized luminescence (CPL) dissymmetry factors (glum), we achieve a linear modulation of glum from 0.153 to near zero via mechanical stretching. These fibers exhibit an exceptionally low optical loss coefficient (~0.0922 dB/mm), ensuring long-range signal integrity. Crucially, the glum signal provides a "self-calibrating" sensing mode inherently robust against excitation fluctuations and environmental scattering-overcoming fundamental limitations of standard intensity-based sensors. This work provides a deeper understanding of strain-regulated photonic architectures, offering a robust platform for high-precision, interference-free human motion monitoring and multi-channel optoelectronic communication.