The transverse patterns of the wave amplitude and/or intensity of a laser beam. The pattern formed is a solution to the paraxial wave equation, and also is affected by the conditions inside the laser cavity. For instance, an intracavity device that chooses a favored set of perpindicular axes will likely result in what is called a Hermite-Gaussian mode - essentially a Gaussian function multiplied by two Hermite polynomials - one in the x-direction, and one in the y-direction. The orders of the Hermite polynomials are determined by the mode indices, which are just parameters that depend on the geometry of the system. More generally, the Hermite-Gaussian modes (and other modes, such as the Laguerre-Gaussian mode) form a basis set for the description of any possible mode.