Fabrication and characterization of amorphous polyethylene terephthalate optical waveguides

Amorphous polyethylene terephthalate (PET) optical waveguides are fabricated by the spin coating method and the optical properties are characterized. The refractive index measured by a spectroscopic ellipsometer is 1.5656, 1.5560, 1.5489, and 1.5477 at 633-, 830-, 1310-, and 1550-nm wavelength, respectively. Multimode optical waveguides with 12-μm thickness and 46-μm width are fabricated by mechanical grinding using a dicing saw to form the core ridge, and the propagation loss is measured by the cut-back method to be 0.30, 0.12, 0.35, and 0.70 dB/cm for 660-, 830-, 1310-, and 1550-nm wavelength, respectively.