ELECTROMAGNETIC-FIELD QUANTIZATION IN AMPLIFYING DIELECTRICS

The electromagnetic field is quantized for normal transmission of inci dent waves through a parallel-sided dielectric slab. The dielectric ma terial is dispersive and it acts as a linear amplifier over limited ra nges of the frequency and as a linear attenuator at the remaining freq uencies. The field operators derived for the three spatial regions wit hin and on either side of the slab are shown to satisfy the canonical commutation relations. The noise fluxes emitted by the slab are evalua ted and shown to satisfy the general requirements for the minimum nois e associated with linear amplifiers and attenuators. The behavior of t he amplifier gain profile on the approach to the lasing threshold of t he slab is determined, but the results are restricted to the below-thr eshold state of the system. The spectra of the electric-field fluctuat ions are evaluated for the three spatial regions and for amplifying an d attenuating frequencies.