REFLOW AND BURIAL OF CHANNEL WAVE-GUIDES FORMED IN SOL-GEL GLASS ON SI SUBSTRATES

A reflow step and an improved burial procedure are demonstrated for channel waveguides formed in sol-gel glass on silicon substrates. Thick sol-gel films are deposited by repetitive spin coating and rapid thermal annealing, and etched to form ridge waveguides. Furnace heating is then used to melt both core and buffer layers simultaneously, providing a smooth surface for burial by further spin-coat deposition. Results are presented for typical core shapes, surface profiles after planarization, and optical insertion losses.