Design and analysis of passively mode-locked all-quantum-dot electrically-driven VECSEL

摘要

Detailed characteristics of newly proposed passively mode-locked vertical-external-cavity surface-emitting laser (VECSEL) are investigated. The active material is a quantum dot (QD) InAs/GaAs lasing at a wavelength of 1.3 mu m. The QD-VECSEL is electrically-driven and is mode-locked by p-i-n QD based semiconductor saturable absorber mirror (SESAM). Time-domain travelling-wave models together with carrier concentration rate equations are employed for investigating the operation of the device. Different parameters that affect the mode-locking performance of the proposed device are examined. Such parameters include the VECSEL to SESAM beam area ratio, the reverse voltage applied to the p-i-n QD-SESAM, the injected current to the VECSEL, and the QD inhomogeneous broadening. The gain, absorption and pulse dynamics are studied, along with the spectral characteristics of the pulse train. The obtained results show that there is a possibility of obtaining mode-locked laser pulses from that device at a wavelength of 1.3 mu m with pulse repetition frequency of 45 GHz and average pulse width of approximately 10 ps.