  By modulating the intensity of laser light before the rotating groundglass,
the well-known pseudothermal light source can be modified into superbunching
pseudothermal light source, in which the degree of second-order coherence of
the scattered light is larger than 2. With the modulated intensities following
binary distribution, we experimentally observed the degree of second- and
third-order coherence equaling 20.45 and 227.07, which is much larger than the
value of thermal or pseudothermal light, 2 and 6, respectively. Numerical
simulation predicts that the degree of second-order coherence can be further
improved by tuning the parameters of binary distribution. It is also predicted
that the quality of temporal ghost imaging can be improved with this
superbunching pseudothermal light. This simple and efficient superbunching
pseudothermal light source provides an interesting alternative to study the
second- and higher-order interference of light in these scenarios where thermal
or pseudothermal light source were employed.
