“…Diode lasers with single-mode oscillation, mode-hop-free wavelength tunability and intrinsic low phase noise through a narrow Schawlow-Townes linewidth are instrumental in many applications. These include communication technology, for instance, to raise the data flow in fiber networks with advanced phase encoding [1], or as on-chip local oscillators for integrated microwave photonics [2]. Other applications include retrieval of information with highest precision, sensitivity, and speed, such as with spectroscopic detection, monitoring and sensing [3,4,5,6], for ranging with diode-driven frequency combs [7,8,9], or to advance time keeping with chip-integrated, portable optical clocks [10].…”