Transform-limited optical pulses from 18 GHz monolithic modelocked quantum dot lasers operating at ~1.3 µm

18 GHz passive modelocking with Fourier-transform-limited optical pulses in InGaAs/GaAs quantum dot lasers emitting at ∼1.3 µm has been achieved for the first time. An upper limit of 600 fs is estimated for the root-mean-square timing jitter (2.5–50 MHz).