High optical coupling efficiency using 45 °-ended fibre for low-height and low-cost optical interconnect modules

High optical coupling efficiency of more than 80% between an optical fibre and a vertical-cavity surface-emitting laser (VCSEL) has been achieved without use of a lens. A 45deg-ended fine-drawn optical fibre can be positioned closer to a VCSEL than a conventional multimode fibre. 12.5 Gbit/s/ch optical signal transmissions using a low-height optical coupling structure have been demonstrated with optical output power as high as +2.0 dBm without use of a lens.