Squeezed thermal radiation state in a Kerr-nonlinear black body

We find that the photon system in the black body filled in its interior by a Kerr-nonlinear crystal is in a squeezed thermal radiation state, in which the photon system possesses a new kind of quasiparticles-nonpolaritons. Th e existence of nonpolaritons should be manifested by observing the predicte d temperature dependence of the velocity and squeezing of nonpolaritons. Th e propagation velocity and noise proper-ties of nonpolaritons constitute po tentially novel and significant effects in solid-state quantum optics and h ence these effects should have extensive application to fields of science a nd technology. (C) 2001 Elsevier Science B.V. All rights reserved.