40 Gbit/s transmission in a silicon-compatible Al2O3:Er3+ integrated optical amplifier

Erbium-doped waveguide amplifiers (EDWAs) are of interest for their potential use in integrated photonic circuits. Unlike semiconductor optical amplifiers (SOAs), which are typically fabricated using costly III-V materials and are limited in their capacity to amplify WDM signals (< 20 Gbit/s per channel) due to transient carrier effects, EDWA fabrication and design is straightforward, they can be processed directly on silicon, and their all-optical operation and long excited-state lifetime mean that amplification at high data rates is feasible. This paper presents results of amplification of a 40-Gbit/s optical signal using an EDWA. Typical eye diagrams with and without the EDWA and lensed fibers are presented. In both cases the eye pattern is open and no significant distortion can be observed with the EDWA included in the transmission setup. No difference in internal net gain was observed for the 40-Gbit/s encoded signal and a continuous-wave signal. Compared to the reference signal, without EDWA and lensed fibers, for a pump power of 220 mW and a signal power of -0.5 dBm coupled into the device, only a small power penalty of approximately 1 dB is observed.