List of Division publications with links

2016-12-02 11:47 - Twist-induced guidance in coreless photonic crystal fiber: A helical channel for light

R. Beravat, G. K. L. Wong, M. H. Frosz, X. M. Xi, P. St.J. Russell, Sci. Adv. 2, e1601421 (2016)

A century ago, Einstein proposed that gravitational forces were the result of the curvature of space-time and predicted that light rays would deflect when passing a massive celestial object. We report that twisting the periodically structured "space" within a coreless photonic crystal fiber creates a helical channel where guided modes can form despite the absence of any discernible core structure. Using a Hamiltonian optics analysis, we show that the light rays follow closed spiral or oscillatory paths within the helical channel, in close analogy with the geodesics of motion in a two-dimensional gravitational field. The mode diameter shrinks, and its refractive index rises, as the twist rate increases. The birefringence, orbital angular momentum, and dispersion of these unusual modes are explored.