Passive mode-locked technology utilizes saturable absorbers’ nonlinear absorption effect to regulate the cavity’s loss and phase to generate mode-locked pulses. Graphene has a unique energy bandgap structure, a low absorption coefficient, a considerable modulation depth, and an ultrawide operating spectral range (300–2,500 nm).
Click here for original story, When graphene serves as a saturable absorber, it can generate two types of mode-locking states
Source: Phys.org