Bandwidth Enhancement in Multimode Polymer Waveguides Using Waveguide Layout for Optical Printed Circuit Boards

Abstract

Dispersion studies demonstrate that waveguide layout can be used to enhance the bandwidth performance of multimode polymer waveguides for use in board-level optical interconnects, providing >40 GHz×m without the need for any launch conditioning.

Flexible Multimode Polymer Waveguide Arrays for Versatile High-Speed Short-Reach Communication Links

“…For overfilled launches however, flexing the waveguides is expected to have a beneficial effect with respect to waveguide bandwidth when compared with the same waveguide without any flexure (straight) under the same launch, as higher order modes are suppressed along the bend reducing therefore multimode dispersion. Similar behaviour has been recorded in in-plane 90°bends and has been reported in [39].…”

“…The relatively large RI difference between core and cladding of ∼0.02, the waveguide's large dimension and its graded-index RI profile provide a strong mode confinement (in comparison to that of single mode or few-mode waveguides) for the modes of lower orders which typically carry the majority of the optical power in such waveguides. The observed performance is similar or even slightly better than that obtained from a 90-degree in-plane waveguide bends fabricated with the same materials and similar waveguide dimensions (1 dB excess loss for a ∼8 mm radius under a 50 µm MMF input) [39]. The difference in performance can be attributed to the difference in the quality between the horizontal and vertical sidewalls of the waveguides.…”

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

“…The results clearly indicate that the bandwidth of the link is limited by the optoelectronic devices used here rather the long spiral waveguide, and demonstrate that the sample bending does not introduce any significant additional dispersion in the link. The obtained results are in agreement with results obtained from bandwidth studies on multimode waveguide bends on rigid substrates [17].…”

“…5(c)], which can be attributed to the suppression of the higher order modes along the waveguide bend. Similar bandwidth improvements have been observed in in-plane polymer multimode waveguide bends when the bend radius is reduced [17]. The results obtained indicate that for the 1 m length, radii and data rates studied here (which are relevant to the application), any mode mixing effects in these polymer waveguides due to flexure are weak and don't significantly affect their data transmission capability.…”

“…Although data transmission at rates up to 25 Gb/s has been reported over flexible polymer multimode waveguides [9,15,16], these demonstrations only High-Speed Data Transmission over Flexible Multimode Polymer Waveguides Under Flexure Nikolaos Bamiedakis, Fengyuan Shi, Daping Chu, Senior Member, IEEE, Richard V. Penty, Senior Member, IEEE and Ian H. White, Fellow, IEEE involved straight waveguides with short lengths of ≤ 20 cm, whilst no particular studies have been carried out on their performance under flexure. Additionally, bandwidth studies on 90° waveguide bends of fixed radius fabricated on rigid substrates have been reported in [17] with good bandwidth performance demonstrated. However, in such rigid waveguide bends with fixed curvature, no stress is induced due to the bending while the length of the bend sections is also very short (~3 cm).…”