Laser Cavity Mode Competition
Gain Saturation · Winner-Take-All · Mode-Locking
Parameters
Pump rate R
1.5
Gain bandwidth Δν
0.3
Mode coupling κ
0.5
Cavity loss γ
0.5
Num modes M
7
Reset Modes
Perturb
dIᵢ/dt = (gᵢ − γ − κΣⱼIⱼ)Iᵢ
gᵢ = R·exp(−(νᵢ)²/2Δν²)
gain saturation: g→g/(1+Σ Iⱼ)
Each longitudinal mode competes for gain. Cross-saturation (κ) drives winner-take-all. When modes lock in phase, pulses emerge (mode-locking). Real lasers: He-Ne, diode, Ti:sapphire all exhibit this competition.
dominant: — | power: —