Electromagnetic Gaussian beams beyond the paraxial approximation

The lowest-order Gaussian beam mode is considered in a high-aperture theory based on a new variation of the complex source point model. To avoid singu larities, combinations of sources and sinks are assumed. The resultant beam is a rigorous solution of Maxwell's equations for all space that reduces t o the conventional Gaussian beam in the paraxial limit and that is physical ly realizable. The field in the region of the waist and far from the waist is explored. It is demonstrated that direct rigorous evaluation of the fiel d is feasible. (C) 1999 Optical Society of America [S0740-3232(99)01205-3] OCIS codes: 050.1.940, 140.3410, 250.5500.