Very low loss channel waveguides in polymethylmethacrylate

Abstract

A unique ultraviolet laser fabrication technique of very low loss channel waveguides in polymethylmethacrylate (PMMA) is reported. Beside low surface and sidewall scattering, the role of bulk scattering in polymeric waveguides was addressed. Linear propagation loss of 0.08 dB/cm in channel waveguides of PMMA at 633 nm was achieved. The experimentally observed one order of magnitude reduction of linear loss due to a selection of maximum size polymers used is qualitatively explained from Mie scattering simulation from bulk polymer medium. This points to the possibility of further reduction of linear propagation loss in polymeric waveguides with reduced dimension of constituent polymers.