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Two polymer technology platforms incorporating both polymer-based materials and UV-assisted and hot embossing fabrication processes have been developed for planar optical waveguiding applications. Firstly, a novel hybrid organic-inorganic (sol-gel) materials system with epoxy functionality has been developed for use in short-range optical interconnect applications. The sol-gel material can be easily formulated and deposited by spin or dip coating to form layers of up to 25μm in thickness. The resulting film can be selectively cross-linked using photo-lithography, as part of a UV-Thermal curing process. The basic refractive index of as-deposited layers can be adjusted between 1.48 and 1.515 by modifying the concentration of DPDMS present. The near-field image of transmitted radiation (633nm) demonstrated waveguiding and efficient light confinement within the UV-thermally produced core regions. Preliminary Telcordia reliability testing indicates that the hybrid material waveguides have good thermo-mechanical stability and meet the requirements for central office (CO) operation. This represents a significant improvement in thermal stability over previous inorganic-organic hybrid waveguide materials systems containing acrylate or methacrylate groups that are easily cured by thermal processes. Secondly, an imprint embossing process has been developed for fabrication of all polymer waveguiding components enabling simultaneous embossing of both waveguide and optical fibre alignment grooves. Optimised pairings of polymer materials for the substrate of the device, into which the waveguide grooves are imprinted, and the core, which provides the refractive index step necessary for guiding light through the device, have been identified and evaluated. Insertion loss measurements were performed at 850 and 1330nm using the cleave-back method and were found to be 0.4dB cm-1 and 0.7 dB cm-1 respectively. The measured waveguide loss from the optimised devices at 850nm after thermal reliability testing was 1.0dB/cm. These measurements indicate that polymer optical waveguides manufactured using this embossing process will satisfy several envisaged optical interconnect datacom applications.
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