  We investigate waveguide-integrated plasmonic graphene photodetector
operating based on the hot carrier photo-bolometric effect, which is
characterized simultaneously by high responsivity on the scale of hundreds of
AW-1 and high speed on the scale of 100s of GHz. We develop a theory of
bolometric effect originating from the band nonparabolicity of graphene and
estimate responsivity due to bolometric effect is shown to significantly
surpass the responsivity of co-existing photo-conductive effect thus
convincingly demonstrating the dominance of bolometric effect. Based on the
theory we propose a novel detector configuration based on hybrid waveguide that
allows for efficient absorption in the graphene over short distance and
subsequently a large change of conductivity. The results demonstrate the
potential of graphene for high-speed communication systems.
