We demonstrate mode locking in a two-section quantum-dot laser that produces output powers up to 45 mW at 1260 nm. The pulse duration could be varied from 2 ps to as short as 400 fs at the 21 GHz pulse repetition rate.

A record broadly tunable high-power external cavity InAs/GaAs quantum-dot diode laser with a tuning range of 202 nm (1122 nm-1324 nm) is demonstrated. A maximum output power of 480 mW and a side-mode suppression ratio greater than 45 dB are achieved in the central part of the tuning range. We exploit a number of strategies for enhancing the tuning range of external cavity quantum-dot lasers. Different waveguide designs, laser configurations and operation conditions (pump current and temperature) are investigated for optimization of output power and tunability.

The authors demonstrate stable mode locking that involves transitions within either the ground state $\left(1260\mathrm{nm}\right)$ or the excited state $\left(1190\mathrm{nm}\right)$ in a two-section quantum-dot laser, at repetition frequencies of 21 and $20.5\mathrm{GHz}$ , respectively. The average power of the mode-locked output was in excess of $35\mathrm{mW}$ for operation in the ground state and $25\mathrm{mW}$ in the excited state. The selection of pulse generation between these states in the mode-locking regime is controlled by the electrical biasing conditions.

We report a dual-wavelength passive mode locking regime where picosecond pulses are generated from both ground (λ = 1263nm) and excited state transitions (λ = 1180nm), in a GaAs-based monolithic two-section quantum-dot laser. Moreover, these results are reproduced by numerical simulations which provide a better insight on the dual-wavelength mode-locked operation.

Click on the title to browse this book