Noise-induced peak intensity fluctuations in class B laser systems

Area of Science:

• Physics
• Nonlinear Dynamics
• Quantum Optics

Background:

• Population systems, such as class B lasers, are susceptible to instabilities driven by random perturbations and noise.
• Noise in these systems can lead to significant fluctuations, particularly affecting electric-field dynamics in lasers.
• Above threshold, laser intensity exhibits transient relaxation oscillations influenced by these noise-induced fluctuations.

Purpose of the Study:

• To investigate the probability distribution of the first intensity peak in class B lasers during transient phases under the influence of noise.
• To establish a connection between the first peak's intensity value and a unique fluctuational momentum.
• To analyze the behavior of small fluctuations in relation to deterministic theories.

Main Methods:

• Utilizing the Wentzel-Kramers-Brillouin (WKB) approximation to calculate the probability distribution of the first intensity peak.
• Analyzing the peak intensity distribution in the limit of a small ratio of photon-to-carrier lifetimes.
• Examining small fluctuations in the context of deterministic theoretical models.

Main Results:

• The study successfully calculates the probability distribution for the first intensity peak in noisy laser systems.
• A direct relationship is demonstrated between each first peak intensity value and a specific fluctuational momentum.
• The behavior of small fluctuations is analyzed and compared with predictions from deterministic theories.

Conclusions:

• The developed Wentzel-Kramers-Brillouin approach provides a method to understand noise-induced transient dynamics in population systems.
• The findings offer insights into the statistical properties of intensity fluctuations in lasers above threshold.
• The methodology is adaptable for analyzing transient, noise-induced large fluctuations in diverse systems exhibiting relaxation dynamics.