Photonics: Double Twist

IME researchers have developed a silicon waveguide based tranverse electrical (TE) mode converter to mitigate against polarization in waveguides - a major roadblock in manufacturing. The proposed converter is designed to convert optical signals between a horizontal and a vertical waveguide (and vice-versa); it also serves as a critical component to realise IME's polarity diversity scheme. The converter demonstrated good polarization extinction ratio of 17 dB at 5 m transition length and an insertion loss of less than 2dB. Compared to reported polarization diversity schemes using mode-coupling-based rotators, the proposed scheme (with the converter) is more fabrication-friendly as it exhibits higher dimensional tolerance.