Low loss InP traveling wave amplifiers with U-bend waveguide for hybrid integration on silicon photonics platform

Development of InP-based U-bend waveguide gain chips for hybrid integration on silicon platform is presented. We utilize Euler bend geometry to ensure small footprint along with low losses. The geometry allows to bring the input and output on the same facet and is used to simplify alignment for lower coupling losses. The interface between bend and straight waveguide is inspected by comparing shallow and deep etched waveguide profiles. The effects of this interface and the bend geometry on the device losses, electric properties and spectrum are reported. Finally, the integration of U-bend gain chips on silicon-on-insulator platform is demonstrated.