Continuous Fourier-transform spline solution of unstable resonator-field distribution

Abstract
To deal with sharply cut off fields at mirror edges, a continuous Fourier integration procedure is described. A spline fit is made to the discrete data, followed by analytic integration of the spline functions. End corrections associated with the difference between spline functions near the edges and the remaining uniform splines are made. This procedure permits an accurate integration of the paraxial equation in the thin-gain-sheet approximation.