High-Speed Data Transmission Over Flexible Multimode Polymer Waveguides Under Flexure

Polymer multimode waveguides on flexible substrates enable the formation of bendable low-cost optical interconnects that can be deployed in a wide range of applications. However, the highly multimoded nature of such guides in combination with the stress and mode mixing induced due to sample bending raise important concerns about the effect that sample flexure has on their bandwidth performance and potential to support high-speed data transmission. In this letter, we present data transmission studies on a 1-m long flexible spiral waveguide when flexure is applied. The flexible polymer sample is bent 180° around a cylindrical mandrel, and the loss and frequency response of the waveguide are obtained for radii of curvature down to 4 mm and are compared with the performance obtained when no flexure is applied. The bit-error-rate (BER) performance of the respective optical link is also recorded at data rates up to 40 Gb/s. A flat frequency response up to at least 30 GHz is demonstrated for all bending radii applied, and error-free (BER<;10
^-12
) data transmission is achieved for all data rates studied up to 40 Gb/s. The results clearly demonstrate that sample flexing does not result in any significant transmission impairments in such links and highlight the strong potential of this technology for use in high-speed board-level interconnections.