Mode discrimination in dissipatively coupled laser arrays.

Area of Science:

• Photonics and optical engineering
• Laser physics
• Quantum optics

Background:

• Laser arrays require effective mode discrimination for stable single-mode operation.
• Understanding the influence of inter-cavity coupling on laser modes is crucial for device design.

Purpose of the Study:

• To investigate the impact of dissipative coupling on the eigenfrequencies and decay rates of optical resonator arrays.
• To analyze how this coupling affects mode discrimination and lasing thresholds in laser arrays.
• To provide an analytical framework for predicting single-mode operation in such systems.

Main Methods:

• Analytical calculation of array supermodes and eigenfrequencies using a tight-binding model.
• Derivation of the single-mode operation range based on the calculated eigenfrequencies.
• Finite element simulation of transversely coupled semiconductor laser cavities to validate theoretical predictions.

Main Results:

• Dissipative coupling creates a ladder of decay rates in complex eigenfrequencies.
• Mode discrimination is promoted, with lowest-order modes having the highest lasing threshold and highest-order modes having the lowest.
• Analytical model accurately predicts supermode behavior and single-mode operation.

Conclusions:

• Dissipative coupling is an effective mechanism for achieving mode discrimination in laser arrays.
• The tight-binding model provides a valuable tool for designing and optimizing laser arrays with specific mode characteristics.
• The findings offer a pathway to engineer laser arrays for enhanced single-mode operation and performance.