A printed nanobeam laser on a SiO₂/Si substrate for low-threshold continuous-wave operation

A small-footprint nanobeam photonic crystal laser made of InGaAsP material is directly integrated on a SiO₂/Si substrate without using adhesive material via transfer-printing processes (i.e., dry transfer-printing). The transferred nanobeam structure with a physical volume of ~6.6 × 0.58 × 0.28 µm(3) (~10.5 (λ/n)3) shows single mode lasing near 1550 nm with continuous-wave (CW) operation at room-temperature, where effective lasing threshold power was as low as 9 µW. This CW operation was achieved mainly due to efficient heat dissipation provided by direct contact between the nanobeam and the substrate. This transfer-printed nanobeam laser could be a promising candidate for the next-generation light source with a feature of low-power consumption in ultracompact photonic integrated circuits.