Technical Symposium Spotlights

The common approach for specifying core geometry in multicore optical fibers (MCF) is to use the core radial position (relative to the cladding center) and the pitch between core pairs. This works well to describe the nominal MCF features but is inadequate to properly tolerance the core positions (i.e. restrict core positional errors in a manufactured MCF). A better approach is to perform an optimized alignment of the manufactured MCF against a “master” template of the MCF design core positions. This approach produces consistent, easily understood limits on core positional errors and generalizes to more complicated core patterns.

Crosslinked polyethylene (XLPE) is widely used in energy cables but is difficult to recycle due to its thermoset nature. As a result, thousands of tons of XLPE waste are landfilled annually. This study investigates a sustainable recycling strategy by mechanically reducing XLPE waste into powder and blending it with polypropylene (PP) to create an injection-moldable composite. An experimental matrix of blends was created to evaluate the effects of XLPE particle size and weight percentage on mechanical and rheological properties. Characterization techniques included tensile and impact testing, melt flow index, and oxidative induction time. Results show that XLPE content significantly affects flow behavior, while particle size plays a larger role in mechanical performance. Optimized blends demonstrated suitable properties for use in non-electrical applications such as cable spool manufacturing. This approach presents a potential avenue for large-scale reuse of XLPE scrap in the wire and cable industry.

Reliable fiber cables must endure temperature cycling without significant signal loss. During manufacturing, installation, and long-term operation, these cables are subjected to a variety of environmental conditions. Temperature fluctuations can induce stress and strain, particularly in loose-tube design where the fiber is free to move. This paper builds off existing work from Henry Rice and Jacob Savoie, applying finite element analysis (FEA) to simulate dry loose-tube cable designs under temperature load [1]. This study aims to improve the simulation model so that it aligns more closely with observed field behavior, better capturing how excess fiber length (EFL), the coefficient of linear thermal expansion (CLTE), and subunit free space contribute to the internal stress placed on the optical fibers. It also demonstrates the viability of the model for predicting the impact of stress on attenuation in finished cables with various materials, fiber counts, and tube sizes. By systematically comparing simulated contact pressure with measured attenuation, this study reinforces the correlation established in previous work, confirming that FEA can yield accurate predictions of temperature-induced attenuation and guide better cable design.