Erbium-doped amplifiers and lossless splitters have been
formed by ion exchange in silicate [2] or phosphate [3] glass
matrixes and by ion implantation into Al O [4]. Topographic
guides have been formed in Er-doped silicate and phosphate
glasses deposited by sputtering [5], [6]. Er-doped guides have
also been formed by plasma-enhanced chemical vapor deposition
(PECVD) [7], [8]. EDWA performance has been compared
in [1]. Internal gains of 4.1 dB/cm have been achieved in
ion-exchanged phosphate glass, 1.1 dB/cm in soda-lime silicate
glass, and 0.6 dB/cm in implanted Al O .