Semiclassical theory of the hyperlens.

We study ray dynamics inside the hyperlens, a device capable of sub-diffraction-limited far-field imaging. An analytical result for the ray trajectories inside the hyperlens is obtained using Hamiltonian optics, which offers an alternative description of the device. It is also found that the ray trajectories can exhibit a unique spiraling nature inside the device. Numerical simulations of plane wave and Gaussian beam scattering from the hyperlens confirm the semiclassical description.