We solve the problem that often arises in optics and charged particle trans
port design tasks of finding a time-dependent Hamiltonian system that produ
ces a given symplectic map. In addition, we show how, given a particular Ha
miltonian, to produce many Hamiltonians that have the same time-one map so
that one has a large class of Hamiltonians from which to choose the 'best'
design. We also show how to produce many symplectic maps that are given exp
licitly rather than implicitly so that the design problem is more tractable
. (C) 1999 Elsevier Science B.V. All rights reserved.