Semiconductor optical amplifiers at 2.0‐µm wavelength on silicon

A semiconductor optical amplifier at 2.0‐µm wavelength is reported. This device is heterogeneously integrated by directly bonding an InP‐based active region to a silicon substrate. It is therefore compatible with low‐cost and high‐volume fabrication infrastructures, and can be efficiently coupled to other active and passive devices in a photonic integrated circuit. On‐chip gain larger than 13 dB is demonstrated at 20 °C, with a 3‐dB bandwidth of ∼75 nm centered at 2.01 µm. No saturation of the gain is observed for an on‐chip input power up to 0 dBm, and on‐chip gain is observed for temperatures up to at least 50 °C. This technology paves the way to chip‐level applications for optical communication, industrial or medical monitoring, and non‐linear optics.