Dynamics of on-chip asymmetrically coupled semiconductor lasers.

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Device Physics
• Nonlinear Dynamics

Background:

• Semiconductor lasers are fundamental components in photonic integrated circuits (PICs).
• Understanding the dynamics of coupled lasers is crucial for designing stable and predictable optical systems.
• Asymmetric coupling introduces complex behaviors that require detailed investigation.

Purpose of the Study:

• To investigate the dynamics of asymmetrically coupled semiconductor lasers on PICs.
• To differentiate the behavior of passive versus saturable coupling waveguides.
• To explore the influence of coupling phase on laser dynamics.

Main Methods:

• Experimental investigation of coupled semiconductor lasers.
• Theoretical modeling using a rate-equation model with a saturable coupling waveguide.
• Bifurcation analysis of laser dynamics.

Main Results:

• Experimental observations are explained by the rate-equation model.
• Passive coupling exhibits dynamics similar to optical injection, insensitive to coupling phase.
• Saturable coupling leads to complex, unpredictable dynamics strongly dependent on coupling phase.

Conclusions:

• The coupling waveguide's nature (passive vs. saturable) significantly impacts laser dynamics.
• Saturable coupling offers complex dynamics but requires careful phase control.
• A simple PIC layout can achieve reproducible laser dynamics.