ABSTRACT
In tlais chapter we present mathematical models for the propagation of Gaussian beams. Topics covered are:
propagation, focal parameters, and focusability behaviors of diverging or converging TEMoo beams
ABCD matrix treatment of TEMoo beams propagating through single or multiple optical elements
Equations for the electric fields for higher-order Gaussian beams
historical evolution and current usage of the M2 beam propagation parameter
