Efficient Hybrid Integration of Long-Wavelength VCSELs on Silicon Photonic Circuits

Abstract

An efficient integration scheme for a vertical cavity surface emission laser (VCSEL) on a silicon photonic circuit is introduced. A grating coupler fabricated on a tilted silicon membrane is used to couple the vertical emission of the VCSEL to the in-plane silicon waveguide with a high coupling efficiency and a low reflection back to the laser. Single-mode and single-polarization VCSELs at 1310nm wavelength band are flip-chip bonded on the silicon photonic chip. A coupling efficiency of -5.8dB is measured at the laser wavelength and a high optical power of 0.66mW is coupled to the silicon waveguide. Data transmission up to 10Gb/s with direct current modulation is realized using the integrated VCSEL. All the structures in the present coupling scheme are massively producible, and the hybrid integration of VCSELs relies on a standard high-accuracy flip-chip process with passive alignment.