A simple technique for fabricating single mode star couplers using ion-exchanged glass guides is proposed and demonstrated. Calculations indicate the possibility of achieving an excess loss of 2dB and a uniformity of 3dB for a lx32 star coupler. Furthermore the technique can be scaled to increase the number of ports without changing uniformity or excess loss.
J. M. Connors,
"Star Couplers Fabricated In Ion-Exchanged Glass Substrates", Proc. SPIE 0993, Integrated Optical Circuit Engineering VI, (6 December 1988); doi: 10.1117/12.960087; https://doi.org/10.1117/12.960087