PHOTON-EMISSION FROM A TIME-VARYING DIELECTRIC MEDIUM IN A CAVITY

Field evolution in a cavity including a time-varying dielectric is stu died by determining the effective Hamiltonian. For a uniform dielectri c, the Hamiltonian is obtained explicitly, and we use it to discuss ph oton creation in the case of an oscillating dielectric constant. It is shown that the mode amplification is similar to that in the case of a moving mirror, but the intermode transition is suppressed. This prope rty enables us to amplify a selected mode alone, unlike in the moving mirror case.