Extreme pulses in gain-switched semiconductor lasers.

Area of Science:

• Optics
• Semiconductor Lasers
• Nonlinear Dynamics

Background:

• Semiconductor lasers driven by strong current modulation produce gain-switched optical pulse trains.
• These lasers can also generate pulse trains at sub-harmonic repetition rates.

Purpose of the Study:

• To investigate the occurrence of extreme optical pulses in gain-switched semiconductor lasers.
• To understand the underlying mechanisms and statistics of these extreme pulses.

Main Methods:

• Experimental observation of extreme pulse generation.
• Numerical modeling of laser dynamics and optical power fluctuations.

Main Results:

• Extreme single-cycle pulses, similar to rogue waves, were observed interrupting normal pulse trains.
• Numerical modeling revealed that drops in circulating optical power precede extreme pulse events.
• Stochastic source terms were identified as dominant factors in optical power fluctuations at the single photon level.

Conclusions:

• Gain-switched semiconductor lasers can exhibit rogue wave-like phenomena.
• The generation of extreme pulses is linked to internal optical power dynamics and stochastic processes.
• Further research into these extreme events could have implications for laser stability and applications.