Neodymium-doped polyimide waveguides were studied for optical amplifier app
lications. Photoluminescence at 890 nm, 1.06 mu m, and 1.33 mu m from neody
mium ions in the polymer matrix was observed. Optical gain of about 8 dB wa
s measured at 1.06 mu m in a 5-cm-long multimode channel waveguide. Phase s
eparation was observed in the doped polyimide. Large scattering losses in t
he waveguides due to the phase separation were reduced by planarizing the l
ayer of doped polyimide with another layer of undoped polyimide. Such a wav
eguide amplifier has potential applications in lossless splitters, lossless
fiber, and waveguide systems with large fanout. (C) 2000 American Institut
e of Physics. [S0003-6951(00)02835-7].