  We propose and demonstrate a compact and simple vector bending sensor capable
of distinguishing any direction and amplitude with high accuracy. The sensor
consists of a short segment of asymmetric multicore fiber (MCF) fusion spliced
to a standard single mode fiber. The reflection spectrum of such a structure
shifts and shrinks in specific manners depending on the direction in which the
MCF is bent. By monitoring simultaneously wavelength shift and light power
variations, the amplitude and bend direction of the MCF can be unmistakably
measured in any orientation, from 0{\deg} to 360{\deg}. The bending sensor
proposed here is highly sensitive even for small bending angles (below
1{\deg}).
