In terms of the normal form (36.2.1) the
satisfy the operator equation
(36.10.1) becomes Airy’s equation (§9.2(i))
, fold: (36.10.6) is an identity.
In terms of the normal forms (36.2.2) and (36.2.3), the
satisfy the following operator equations
Equation (36.10.17) is the paraxial wave equation.