Glass Waveguides with 0.01 dB/cm Bend Loss for High-Speed, High-Density Optical Fan-Out for Co-Packaged Optics

Low bend loss (0.01 dB/cm, R>6 mm, λ=1310 nm) ion-exchanged waveguides in optimized glass (heat-resistant, >5-year, 110°C), enabled compact fan-outs for fiber-to-chip pitch conversion (16-waveguide, ≥50-μm pitch), <0.3 dB fiber-coupling loss, and O-band 400 Gbit/s PAM4 transmission.