  The chiral surface states of Weyl semimetals have an open Fermi surface
called Fermi arc. At the interface between two Weyl semimetals, these Fermi
arcs are predicted to hybridize and alter their connectivity. In this letter,
we numerically study a one-dimensional (1D) dielectric trilayer grating where
the relative displacements between adjacent layers play the role of two
synthetic momenta. The lattice emulates 3D crystals without time-reversal
symmetry, including Weyl semimetal, nodal line semimetal, and Chern insulator.
Besides showing the phase transition between Weyl semimetal and Chern insulator
at telecom wavelength, this system allows us to observe the Fermi arc
reconstruction between two Weyl semimetals, confirming the theoretical
predictions.
