Fabrication of graded-index core polymer optical waveguides enabling low loss with small bend radius (∼1 mm) using high Δ resins

In this paper, circular graded-index (GI) core polymer optical waveguides are fabricated using the Mosquito method, applying a combination of resins with a high refractive index difference (<i>Δ</i>) for their core and cladding materials. Optical properties of the fabricated waveguides are thoroughly evaluated. These waveguides are expected to exhibit strong optical confinement in their cores due to the synergistic effects of the high <i>Δ</i> and GI refractive index profile. Notably, the experimentally fabricated multimode polymer optical waveguides achieve a bending loss of less than 0.1 dB, even under extreme conditions involving a 90° bend with a bend radius as small as 1 mm.