Quantum-dot external-cavity passively modelocked laser with high peak power and pulse energy

An InAs quantum-dot external-cavity passively modelocked laser with an operation wavelength of 1.27 mu m is demonstrated, based on a two-section quantum-dot superluminescent diode with bending ridge waveguide and a 96% output coupler. Stable modelocking with an average power up to 60 mW was obtained at a repetition frequency of 2.4 GHz. This performance corresponds to a 25 pJ pulse energy obtained directly from the oscillator, which represents a 55-fold increase in pulse energy when compared to the current state-of-the-art for semiconductor lasers. At a repetition frequency of 1.14 GHz, picosecond optical pulses with 1.5 W peak power are also demonstrated, representing the highest peak power achieved from an external-cavity laser at the 1.3 mu m waveband, without the use of any pulse compression or optical amplification.