Neodymium-complex-doped, photo-defined polymer channel waveguide ampliers

Channel waveguides based on a polymer, 6-fluorinated-dianhydride/epoxy, which is actively doped with a Nd complex, $Nd(thenoyltrifluoroacetone)_{3}$ 1,10-phenanthroline, are fabricated by a simple and reproducible procedure, spin coating a photodefinable cladding polymer onto a thermally oxidized silicon wafer, photopatterning, backfilling with the active core polymer, and spin coating with an upper cladding layer. Photoluminescence at 1060 nm from the $Nd^{3+}$ ions with a lifetime of 130 μs is observed. Optical gain at 1060 nm is demonstrated in channel waveguides with different $Nd^{3+}$ concentrations. By accounting for the waveguide loss of 0.1 dB/cm, an internal net gain of 8 dB is demonstrated for a 5.6-cm-long channel waveguide amplifier. Owing to the nature of the $Nd^{3+}$ complex, energy-transfer upconversion affects the gain only at $Nd^{3+}$ concentrations above $1 x 10^{20} cm^{-3}$.