Micro-transfer printing of GaSb optoelectronics chips for mid-infrared silicon photonics integrated circuits

3D integration of GaSb-based gain chips on a silicon photonics platform using micro-transfer printing is demonstrated for the first time. The release process of GaSb coupons, and their transfer for the demonstration of hybrid GaSb/Silicon-photonics on-chip external cavity lasers is reported. A methodology to evaluate the key features of the gain chip coupons, namely the quality of the etched facets and the facet coating deposited using a wafer-level process, is introduced. The characterization provides insight into the fabrication factors limiting the performance of the gain coupons. The level of performance achieved for the transfer printing process offers a solid landmark for the development of photonics integration technology operating at the 2-3 $\mu$m wavelength range. This is instrumental for the deployment of mid-IR photonic integration technology in emerging applications related to gas and biomarker sensing.