We introduce an analogy strategy to design transformation optical devices.Based on Oils the similarities between field lines in different physical systems, the trajectories of light can be intuitively determined to curve in a gentle manner, and the resulting materials are isotropic and nonmagnetic.Furthermore, the physical meaning of the analogue problems plays a key role in the removal of dielectric singularities.We illustrate this approach by Mop Head creating two designs of carpet cloak and a collimating lens as representative examples in two- and three-dimensional spaces, respectively.
The analogy strategy not only reveals the intimate connections between different physical disciplines, such as optics, fluid mechanics and electrostatics, but also provides a heuristic pathway to designing advanced photonic systems.