CORRELATION OF RADIATION-FIELD GROUND-STATE FLUCTUATIONS IN A DISPERSIVE AND LOSSY DIELECTRIC

The correlation of the quantum-mechanical ground-state fluctuations of the electric-field strength in a dispersive and lossy linear dielectric are studied in terms of the symmetrized autocorrelation function, with special emphasis on the optical frequency domain. Starting from the canonical quantization scheme developed by Huttner and Barnett [Phys. Rev. A 46, 4306 (1992)], the analysis is based on a quantization of the phenomenological Maxwell theory, the effect of the medium being described by a frequency-dependent complex permittivity. In this way, the spectrally resolved ground-state autocorrelation function of the electric-field strength can be expressed in terms of the real and imaginary parts of the refractive index. Both analytical and numerical results are presented and the effects of dispersion and absorption including their dependence on the frequency interval chosen are discussed. A comparison with the vacuum fluctuations in free space is given. © 1995 The American Physical Society.