Hybrid-integrated extended cavity mode-locked laser using SiN and a generic III/V platform

Current fiber-based mode-locked lasers are already used in several applications, such as laser eye surgery and spectrograph calibration in the hunt for exoplanets. Miniaturizing and integrating such lasers can enable mass production which could result in new applications, for example distributed sensing of greenhouse gasses [1] and high-performance ranging [2] . Currently, the best performing integrated mode-locked lasers use an extended on-chip cavity. These have been shown on single chips in several III/V and heterogeneous platforms, by using active waveguides for gain, and passive waveguides for the low loss extended cavity [3] , [4] . In this work, these lasers are improved upon by butt-coupling an SiN extended cavity to the gain waveguides in a generic III/V platform, replacing the relatively lossy passive InP waveguides.