  Multicolor Panoramic Photometer-Polarimeter (MPPP) with a time resolution of
1 microsecond has been built based on a PSD and used at the 6-meter telescope
in SAO (Russia). The device allows registration of the photon fluxes in four
photometric bands simultaneously and finding values of 3 Stokes parameters.
MPPP consists of Position-Sensitive Detector (PSD), acquisition MANIA-system,
polarization unit and a set of dichroic filters. MPPP gives a possibility of
detecting photons in 2 pupils with a size of 10 - 15 arc sec centered on the
object and comparison star positions simultaneously. The first half of the
object photon flux passes through the phase rotating plate and polarizer, and
the second one through the polarizer alone. MPPP registers in each of the 4
filters four images of the object with different orientations of polarization
plane and one image of a comparison star. It allows measuring instantaneous
Stokes parameters. The main astrophysical problems to be solved with MPPP are
as follows: investigation of optical pulsars; study of GRB phenomenon in the
optical range; searching for single black holes; study of fast variability of
X-ray binaries. As an illustration of MPPP use, the results of observations at
the 6-meter telescope of Crab pulsar and soft gamma repeater are presented.
