Slab waveguide star coupler for multimode optical fibres

The letter proposes a slab waveguide optical star coupler for multimode fibres, and shows the experimental results of a 15-port optical star coupler. The excess loss was about 2 dB and output power deviation among the ports was ±0.5 dB. Although the reported star coupler has 15 ports, there is no limit to the number of ports possible.