A 4 cm long Er-doped Al2O3 Spiral waveguide amplifier was fabricated o
n a Si substrate, and integrated with wavelength division multiplexers
within a total area of 15 mm(2). When pumped mm with 9 mW 1.48 mu m l
ight from a laser diode, the amplifier shows 2.3 dB net optical gain a
t 1.53 mu m. The gain threshold was 3 mW. The amplifier was doped with
Er by ion implantation to a concentration of 2.7 x 10(20) cm(-3). The
data agree well with calculations based on a model which includes the
effects of cooperative upconversion and excited state absorption. For
an optimized amplifier, net optical gain of 20 dB is predicted. (C) 1
996 American Institute of Physics.