Gain Saturation

Gain saturation occurs when a light amplifier or laser medium has been stimulated to produce more light, but at a certain point, increasing the input energy no longer results in proportional increases in output. Essentially, the material's ability to amplify light becomes maxed out because its available energy states are fully occupied. This leads to a plateau in amplification, limiting the maximum brightness or power achievable. It’s similar to pushing a swing: after a certain point, adding more effort doesn't make it go higher because the system is already operating at its capacity.