  A special class of anisotropic media, hyperbolic metamaterials and
metasurfaces (HMMs), has attracted much attention in recent years due to its
unique abilities to manipulate and engineer electromagnetic waves on the
subwavelength scale. Because all HMM designs require metal dielectric
composites, the unavoidable metal loss at optical frequencies inspired the
development of active HMMs, where gain materials is incorporated to compensate
the metal loss. Here, we experimentally demonstrate an active type II HMM that
operates at vacuum wavelength near 750 nm on a silicon platform. Different from
previous active HMMs operating below 1 {\mu}m, the dielectric constituent in
our HMM is solely composed of gain medium, by utilizing solution processed and
widely tunable metal halide perovskite gain. Thanks to the facile fabrication,
tunability and silicon compatibility of our active HMM, this work paves the way
towards HMM's integration into on chip components, and eventually, into
photonic integrated circuits.
