An intensity-dependent light modulating device involves a light successively
passing
through a polarizer, a first phase retardation plate and a first light modulator.
The light then strikes a mirror and passes one again through the light modulator
and the phase retardation plate in the opposite direction. The light then strikes
an analyzer that is crossed relative to the polarizer. The light modulator and
the phase retardation plate are respectively located in an electric field in which
the indicatrices of the light modulator and the phase retardation plate are deflected,
the deflection of the indicatrix of the light modulator being intensity-dependent.
Due to the passage of light through the phase retardation plate and the light modulator,
an intensity-dependent rotation of the direction of polarization occurs in such
a way that higher intensity light is filtered in the analyzer while lower intensity
light is transmitted.