Saudi petrochemicals and plastics giant Sabic (Riyadh; www.sabic.com) has introduced Ultem 3310TD, a polyetherimide (PEI) resin with a coefficient of thermal expansion (CTE) said to be lower than standard Ultem grades.

The company quoted the material’s CTE at ~38 ppm/C, a 30% reduction versus its Ultem 1010 resin widely used in multi-mode optical transceiver lenses.

The latest material is said to be suited for making optical transceiver collimator lenses used in single-mode fibre optics, an emerging datacentre infrastructure technology for high-speed transmission of large data volumes over long distances. Low CTE is essential to optimise the dimensional stability of collimator lenses and ensure alignment with single-mode fibres.

Heat and temperature fluctuations generated by high data transmission can cause expansion and shrinkage in optical lenses, which can become misaligned with the optic fibres, leading to signal loss or distortion.

The company said the grade can be used to make replacements for traditional aspherical glass lenses in single-mode fiber optic applications as it provides better design and production capability, potential cost savings, and near-infrared transmission without degrading signal quality.

The product can be micromoulded into a wide variety of shapes, multichannel lens arrays, and free-form optics without costly and time-consuming secondary operations of grinding and polishing required for glass lenses, the supplier said.

Single-mode fibre optic systems have a smaller core diameter (8-9 µm) compared to multi-mode fiber optic systems (50-62.5 µm), making dimensional stability an even more critical challenge, said Sabic. The material can potentially be used in other telecommunications applications such as optical modems and optical cables, or considered for components requiring low CTE and good IR transmission, such as LiDAR sensors, drones, and robots.