ABSTRACT
An experimental study of the dynamics of a single-mode quantum-dot semiconductor laser undergoing optical injection is described for the first time, to our knowledge. In particular, the first observation of excitable pulses near the locking boundaries for both positive and negative detuning is reported, indicating locking via a saddle-node bifurcation for both signs of the detuning. The phase evolution of the slave electric-field during pulsing was measured and confirmed that the pulses result from 2pi phase slips. The interpulse-time statistics were analyzed, and a Kramers-like distribution was obtained.
ABSTRACT
Using a multi section laser in coupled cavity injection grating design based on 1.3 microm InGaAs/GaAs quantum dot (QD) active region we were able to enhance the 3 dB modulation bandwidth well beyond the inherent material modulation bandwidth. The material bandwidth was determined by measurements on distributed feedback (DFB) devices to approximately 8 GHz. The special multisectional design allows interaction between the lasing mode and a second mode used as catalyst and enables a high resonance frequency of the device. Based on active QD material this approach allowed us to reach a cut off frequency of 20 GHz in the small signal response of the device.
