Transfer-printing-based integration of a III-V-on-silicon distributed feedback laser

An electrically pumped DFB laser integrated on and coupled to a silicon waveguide circuit is demonstrated by transfer printing a 40 × 970 μm² III-V coupon, defined on a III-V epitaxial wafer. A second-order grating defined in the silicon device layer with a period of 477 nm and a duty cycle of 75% was used for realizing single mode emission, while an adiabatic taper structure is used for coupling to the silicon waveguide layer. 18 mA threshold current and a maximum single-sided waveguide-coupled output power above 2 mW is obtained at 20°C. Single mode operation around 1550 nm with > 40 dB side mode suppression ratio (SMSR) is realized. This new integration approach allows for the very efficient use of the III-V material and the massively parallel integration of these coupons on a silicon photonic integrated circuit wafer. It also allows for the intimate integration of III-V opto-electronic components based on different epitaxial layer structures.