ИСТИНА

A single-layer graphene saturable absorber is employed for passive Q-switching of an Er,Yb:GdAl3(BO3)4 (Er,Yb:GdAB) compact laser, representing the first Er-doped oxoborate laser Q-switched by graphene. This laser is based on a c-cut 1.8 at.% Er3+, 15 at.% Yb3+:GdAB crystal diode-pumped at 0.976 µm. It generates a maximum average output power of 360 mW at 1.55 µm with a slope efficiency of 23% (with respect to the incident power). Stable ~1 μJ / 130 ns pulses are achieved at a repetition rate of 400 kHz. This result represents the shortest pulse duration ever achieved in bulk Er lasers Q-switched by 2D-materials. Graphene is a promising material for generating nanosecond pulses at high repetition rates (MHz-range) in Er-doped oxoborate lasers emitting in the eye-safe range at 1.5-1.7 μm.