Fabrication and optical characterization of sub-micronic waveguide structures on UV210 polymer

In this paper, we report on the interest in a new polymer, UV210, in the field of integrated optics. As 400 nm wide and 1 µm high UV210 rib waveguides have been obtained by deep ultraviolet (DUV) lithography and controlled by scanning electron micrographs (SEMs), they allow us to realize sub-wavelength structures by way of easy and cheap processes. Structural and optical investigations have been carried out on UV210 resist as a function of exposure to DUV light. On the one hand, structural properties through ellipsometric measurements have been investigated: the UV210 refractive index increases with the DUV exposure dose, yielding a large index contrast at 980 nm between areas exposed or not (Δ n = 2 × 10 − 2 ). It is expected that we shall soon be able to photo-print nanometric patterns onto UV210 films. On the other hand, optical studies of propagation losses measured in both irradiated and unexposed single-mode UV210 waveguides have been performed by a cut-back method. Concerning as-deposited rib waveguides, optical losses for TE 00 and TM 00 optical modes have been evaluated to 3.4 ± 0.4 dB cm − 1 and 6.2 ± 0.5 dB cm − 1 , respectively. Hence, the UV210 polymer appears to be a promising candidate for the development of low-cost nanometric structures for miniaturized optical chips, with numerous applications in telecommunication and sensor technology.