FABRICATION OF RIDGE WAVE-GUIDES - A NEW SOLGEL ROUTE

Passive ridge waveguides can be deposited on silicon by a solvent-assi sted lithographic process incorporating simple mask technology and pho tosensitive solgel-derived glasses. Thick films (similar to 4 mu m) ar e dip coated in one step, and channel waveguides and power splitters a re imprinted in them by UV light through appropriate masks. Unexposed regions of the glass are removed by soaking of the films in n-propanol . The remaining ridges are then treated at 200 degrees C and planarize d with a solgel cladding layer. Circular mode profiles are observed fr om ridge guides covered with the cladding. The waveguides are characte rized with scanning electron microscopy, atomic force microscopy, surf ace profilometry, ellipsometry, and fiber end coupling. Overall, the p rocedure is simple and reproducible and leads to waveguides with low l oss, of the order of 0.13 dB/cm. (C) 1998 Optical Society of America.