  Development of reliable photon number resolving detectors (PNRD), devices
which are capable to distinguish 1,2,3.. photons, is of a great importance for
quantum optics and its applications. A new class of affordable PNRD is based on
multipixel photon counters (MPPC). Here we review results of experiments on
using MPPCs for direct characterization of squeezed vacuum (SV) states,
generated via parametric downconversion (PDC). We use MPPCs to measure the
second order normalized intensity correlation function (g^(2)) and directly
detect the two-mode squeezing of SV states. We also present a method of
calibration of crosstalk probability in MPPCs based on g^(2) measurements of
coherent states.
