Paraxial theory of planar integrated systems

We discuss the paraxial approximation for optical systems with an oblique orientation of the optical axis. Our investigation provides modifications necessary to adapt the parabolic approximation of conventional optics to planar integrated free-space optics. Our results are applied to a planar imaging system. For a single-lens system we discuss a design for arbitrary magnification factors. In addition, we calculate the space–bandwidth product of the imaging system, considering geometrical constraints of the concept of planar integration. This provides an upper bound for the number of spatial data channels that can be realized with planar optics.