Fig. 4: Subharmonic pumping using a gain-switched Fabry–Perot laser.
From: Gain-switched semiconductor laser driven soliton microcombs
a Schematic of the subharmonic pulse-pumping method. b GSL spectra obtained with the master laser injecting around the centre of a lasing mode at 1550.7 nm (upper panel) and between two lasing modes (lower panel), respectively. The grey stripes indicate the positions of the central mode’s two neighbouring FP modes. The red dashed lines indicate the positions of the injection. c The measured autocorrelation traces of the GSL pulses in single-mode lasing (upper panel) and dual-mode lasing (lower panel) states, respectively. d The optical spectrum of the soliton microcomb driven by the offset-injection-locked FP GSL. The insets show the enlarged partial spectra of the GSL comb with fgs of 4.86 GHz and the microcomb with frep of 9.72 GHz, respectively.
