gain parameters

Tutorial: Understanding the Gain Parameters in the Virtual Lab

The gain_info parameters control how each laser amplifies light, responds to pumping, and saturates as intensity builds up. By default, these values are chosen to reproduce the behavior of the physical lab. However, they can also be adjusted to explore alternative dynamical regimes in the emulator.

In simple terms:

• The coupling matrix defines how lasers interact.
• The gain parameters define how each laser behaves internally.

Together, they determine how the system evolves toward a steady state.

Used carefully, they allow you to:

• Reproduce hardware behavior
• Explore alternative theoretical regimes
• Study stability and convergence mechanisms

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Overview of the Gain Parameters

 

Parameter	What It Controls Physically	What You Will Observe When Changing It
gain_info_initial_gain	Initial amplification strength	Higher values accelerate intensity buildup but may increase transient oscillations. Lower values slow convergence.
gain_info_pump_max	Strength of external energy injection	Increasing it raises overall intensity and can improve locking robustness. Excessively high values may reduce stability.
gain_info_pump_tau	Speed of gain adaptation (carrier lifetime)	Smaller values produce faster response and shorter transients. Larger values create slower, smoother dynamics.
gain_info_pump_threshold	Distance from lasing threshold	Operating closer to threshold increases sensitivity to coupling and noise. Farther above threshold yields stronger emission and more stable behavior.
gain_info_amplification_saturation	Nonlinear gain suppression	Stronger saturation stabilizes intensity growth. Weaker saturation allows larger intensity variations and stronger nonlinear effects.

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Practical Guidance

Start with default values when comparing to the Physical Lab.

How to Use This Table

• If convergence is too slow → examine initial_gain or pump_tau.
• If intensity is too weak → adjust pump_max or pump_threshold.
• If the system is unstable → increase amplification_saturation.
• If locking seems overly sensitive → check distance from threshold.

Note: small changes can significantly alter system dynamics.

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