With , the TEM00 mode is the lowest order. It is the fundamental transverse mode of the laser resonator and has the same form as a Gaussian beam. The pattern has a single lobe, and has a constant phase across the mode. Modes with increasing show concentric rings of intensity, and modes with increasing show angularly distributed lobes. In general there are spots in the mode pattern (except for ). The mode, the so-called "doughnut mode", is a special case consisting of a superposition of two modes (), rotated with respect to one another.