Multilayer Hybrid Waveguide Amplifier for Three-Dimension Photonic Integrated Circuit

In this letter, a multilayer hybrid waveguide that can be applied to compensate the loss of three-dimension photonic integrated circuit is designed. The multilayer waveguide structure consists of grade index ion-exchange Er³⁺-Yb³⁺ co-doped phosphate planar waveguide, step index polymer rectangular waveguide, and heating electrode. Er³⁺-Yb³⁺ co-doped phosphate layer is to provide stable amplification performance. Polymer waveguides are designed to control the optical field distribution. The operating temperature is adjusted using the heating electrode. The optical field of signal light and pump light of the hybrid structure is simulated by finite difference method. The six-level model is introduced to calculate the gain characteristic of the hybrid waveguide amplifier with different Er³⁺ concentrations and operating temperatures. The optimized gain of the hybrid structure can be up to 4 dB/cm with the signal power of 0.1 mW and pump power of 200 mW. This hybrid waveguide can be used in the loss compensation and tunable vertical power splitter area.