Pulse generation and compression via ground and excited states from a grating coupled passively mode-locked quantum dot two-section diode laser

The authors generate and compress short pulses via the ground and excited state transitions from a passively mode-locked grating coupled quantum dot two-section diode laser at a repetition rate of 2.7GHz. The selection and isolation of either the ground state or excited state transition were performed by an angle tuning of the grating. The externally compressed pulse widths are 970fs from the ground state and 1.2ps from the excited state transition. The sign of the chirp is up chirped for both state transitions.