Hybrid organic-inorganic platforms for passive polymeric single-mode optical waveguides (Conference Presentation)

Optical waveguides and integrated optical devices are increasingly applied in biomedical fields, including optogenetics and sensing. This study presents the fabrication and characterization of flexible single-mode optical waveguides. Polydimethylsiloxane (PDMS) was used as the waveguide cladding, with a core made from zinc oxide (ZnO) nanoparticles mixed with PDMS. Fabrication was performed on polystyrene substrates via spin-coating, achieving a 2 µm core thickness. Morphological analysis was conducted using scanning electron microscopy (SEM), while Fourier-transform infrared spectroscopy (FTIR) characterized the molecular structure. Optical properties, including waveguiding and refractive indices, were measured by the prism coupling technique at 632.8 nm. Insertion optical loss was determined with the cut-back method, with the best samples exhibiting a transmission loss of approximately 0.53 dB cm−1. Tensile tests confirmed reduced mechanical mismatch with tissue compared to most polymeric waveguides. This novel flexible, single-mode waveguide structure is promising for innovative photonic devices and chronic neural interfaces.