  In traditional Hanbury Brown and Twiss (HBT) schemes, the thermal
intensity-intensity correlations are phase insensitive. Here we propose a
modified HBT scheme with phase conjugation to demonstrate the phase-sensitive
and nonfactorizable features for thermal intensity-intensity correlation
speckle. Our scheme leads to results that are similar to those of the
two-photon speckle. We discuss the possibility of the experimental realization.
The results provide us a deeper insight of the thermal correlations and may
lead to more significant applications in imaging and speckle technologies.
