Low Noise Ultrashort Pulse Generation by Direct RF Modulation at 22 GHz From an AlGaInAs Multiple Quantum-Well Laser at 1.55 $\mu{\rm m}$

We report subpicosecond pulse generation at 22 GHz from a two-section passively mode-locked laser at 1.55 $\mu{\rm m}$ , using a novel AlGaInAs quantum-well wafer. By carefully designing the metal pad and the isolation layer, we are able to hybridly mode-lock the laser by modulating the saturable absorber at the fundamental repetition rate and thus achieve a low timing jitter of ${\sim}{\rm 280}~{\rm fs}$ (1 Hz–100 MHz).