Hello, I've been going through some cavity material and attempted analyses regarding transverse modes. Invariably, they always deal with general solutions of paraxial equation and do not have solutions specific to specific cavities I do know that general solutions to paraxial equation are HG, LG , IG modes. What do you do if you want to know what transverse modes you will get for a given cavity a priori? I mean.. cavity specific solutions will depend on dimensions of your cavity. So, shouldn't those dimensions be your inputs ??