  We demonstrate a platform for implementing quantum walks that overcomes many
of the barriers associated with photonic implementations. We use coupled
fiber-optic cavities to implement time-bin encoded walks in an integrated
system. We show that this platform can achieve very low losses combined with
high-fidelity operations, enabling an unprecedented large number of steps in a
passive system, as required for scenarios with multiple walkers. Furthermore
the platform is reconfigurable, enabling variation of the coin, and readily
extends to multidimensional lattices. We demonstrate variation of the coin bias
experimentally for three different values.
