Synchronous Dual-Pulse with Dual-Wavelength Passively Mode-Locked VECSEL

A synchronous dual-pulse with dual-wavelength mode-locking operation was demonstrated in a vertical-external-cavity surface-emitting laser (VECSEL) using a birefringent filter. A wavelength interval of 8.67 nm between 975.42 and 984.09 nm was achieved. The mode-locked laser operated at a repetition rate of 648 MHz, a pulse width of 2.67 ps, a maximum output power of 41.74 mW, and a root-mean-square power fluctuation of 0.28% in 60 min. Furthermore, a wavelength-tunable mode-locked operation with a tuning range of 12.01 nm was achieved, maintaining a repetition rate of 648 MHz and a pulse duration of 2.35 ps. These results demonstrated a promising approach for the stable generation of synchronized, dual-wavelength ultrafast pulses in the VECSEL system.