Misaligned cavities can be described by a 3 x 3 extension of the well-known ABCD matrix approach to aligned cavities. There is a corresponding Huygens integral (HI) formulation for the evolution of the field within such a cavity. We derive a differential 'master' equation (ME) formulation which yields identical eigenmodes and eigenvalues to this HI. This ME is fully equivalent to the HI for linear problems, while providing a more convenient route to the analysis of nonlinear behaviour in such cavities.
- generalized beam matrices