  We demonstrate operation of a small Fabry-Perot interferometer in which
highly coherent Aharonov-Bohm oscillations are observed in the integer and
fractional quantum Hall regimes. Using a novel heterostructure design, Coulomb
effects are drastically suppressed. Coherency of edge mode interference is
characterized by the energy scale for thermal damping, ${T_0=206}mK$ at
$\nu=1$. Selective backscattering of edge modes originating in the ${N=0,1,2}$
Landau levels allows for independent determination of inner and outer edge mode
velocities. Clear Aharonov-Bohm oscillations are observed at fractional filling
factors $\nu=2/3$ and $\nu=1/3$. Our device architecture provides a platform
for measurement of anyonic braiding statistics.
