Effective dielectric and photoelastic tensors of superlattices in the long-wavelength regime

The effective photoelastic constants of a superlattice made of thin alternating layers of orthorhombic symmetry (with principal axes along the superlattice axis) are derived as a function of dielectric, elastic, and photoelastic constants of the constituents. As a first step in this calculation we also obtain the effective dielectric constants of the superlattice for any symmetry of the constituents.