  We present fabrication and optical characterization of micro-cavities made of
multilayer graphene (MLG) cantilevers clamped by metallic electrodes and
suspended over Si/Si02 substrate. Graphene cantilevers act as a
semi-transparent mirrors closing an air-wedge optical cavity. This simple
geometry implements a standing-wave optical resonator along with a mechanical
one. Equal thickness interference fringes are observed in both Raman and
Rayleigh backscattered signals with interfringe given by their specific
wavelength.Chromatic dispersion within the cavity makes possible spatial
modulation of graphene Raman lines and selective rejection of the silicon
background signals. Electrostatic actuation of the multilayer graphene
cantilever by gate voltage tunes the cavity length and induces space and time
modulation of backscattered light including Raman lines. We demonstrate the
potential of those systems for high sensitivity Raman measurements of generic
molecular species grafted on multilayer graphene surface. The Raman signal of
the molecular layer can be modulated both in time and in space in a similar
fashion and show enhancement with respect to a collapsed membrane.
