Maker fringes revisited: second-harmonic generation from birefringent or absorbing materials

We present a new formulation of Maker fringes in parallel-surface films, using self-consistent boundary conditions for reflections and allowing for any degree of refractive-index dispersion. This treatment of the second-harmonic reflections and dispersion, unlike a number of previous derivations, leads correctly to the expected form for the effective second-harmonic d coefficients. Complete expressions with physically meaningful factors are given for the generated second-harmonic power for either absorbing or birefringent films including reflections for the case of no pump depletion. A comparison with the isotropic approximation is given, and practical considerations in the use of these expressions for the fitting of experimental data are discussed.