Optical waveguide amplifiers for heterogeneous integration in optical backplanes

Large-core, tapered Al₂O₃:Nd³⁺ channel waveguides have been fabricated and optical amplification at a wavelength of 880 nm is characterized. Amplification in optical backplanes are demonstrated by inserting such Al₂O₃:Nd³⁺ channel waveguides in between two polymer waveguides. A maximum 0.21-dB internal net gain are demonstrated in an Al₂O₃:Nd³⁺ waveguide coupled in between two polymer channel waveguides. The gain can be improved by increasing the pump power and adjusting the waveguide geometry and dopant concentration for the chosen pump power. Use of such rare-earth-ion-doped waveguide amplifiers can provide a solution for compensating the losses occurring in optical interconnects.