  Utilizing the similarity between the spinor representation of the Dirac
equation and the Maxwell equations that has been recognized since the early
days of relativistic quantum mechanics, a quantum lattice (QLA) representation
of unitary collision stream operators of Maxwell equations is derived for both
homogeneous and inhomogeneous media. A second order accurate 4 spinor scheme is
developed and tested successfully for two dimensional (2D) propagation of a
Gaussian pulse in a uniform medium while for normal (1D) incidence of an
electromagnetic Gaussian pulse onto a dielectric interface requires 8 component
spinors. In particular, the well-known phase change, field amplitudes and
profile widths are recovered by the QLA asymptotic profiles. The QLA
simulations yield the time dependent electromagnetic fields as the pulse enters
and straddles the dielectric boundary. QLA involves unitary interleaved
noncommuting collision and streaming operators that can be coded onto a quantum
computer. The noncommutation being the only reason why one perturbatively
recovers the Maxwell equations.
