Hi, guys. I'm interrest in the question about how optical (laser) resonator can generates the standing wave? As i know, there is a condition that the resonator base (lenght between two mirrors) should be multiple to the lenght of the wave. (L=k*(lamda/2)). But in practice no one never measures the distance between the mirrors of the resonator when creating the laser system. So i would like to ask you, how actually laser resonator can generates the standing wave without the measuring the distance between two mirrors?