Photon Emission from a Time-Varying Dielectric Medium in a Cavity

Nuri Ünal

C. K. Law

We study the quantized field in a one-dimensional electromagnetic resonant cavity. The cavity contains a linear and lossless dielectric medium with frequency-independent polarizability. The dielectric permittivity is an externally prescribed function of both the space and the time. We also allow one of the cavity's mirrors to move in a given trajectory. Unlike other previous studies on the same system, we formulate an effective Hamiltonian so that the dynamics of the cavity field can be described in the Schr\"odinger picture. The effective Hamiltonian is quadratic in structure, therefore two-photon generation from the vacuum state can occur. We also discuss the case of resonant behavior of the system.

Ali A. Kamli

Spontaneous emission in a three-level atom is investigated inside a dielectric cavity between asymmetrically photonic crystals. The photonic crystals are treated within the effective medium approach and the modes dispersions and field amplitudes are determined. The atomic probability amplitudes and spontaneous emission spectra are evaluated for different atomic and cavity parameters. The probability amplitudes show interference effects due to spontaneous emissions from the upper levels to the lower level. Interesting features arise for the variations of the probability amplitudes and spontaneous emission spectra with the variations of frequency near the photonic crystals including dark lines and multi-peaks.

Liping Fu, Chang‐Kui Duan, Guang‐Can Guo

А. Н. Ораевский

Ali A. Kamli, M. Babiker

The spontaneous-emission rate is evaluated for dipole emitters situated in the thin slab region between two semi-infinite one-dimensionally periodic photonic crystals, a situation reminiscent of planar cavity laser structures. It is pointed out that the long-wavelength electromagnetic fields supported by such complex structures can be directly quantized provided that the pair of semi-infinite photonic crystals are treated within the effective-medium approach, in which each photonic crystal is represented by a truncated uniaxial medium whose dielectric tensor components are determinable in terms of layer thicknesses and dielectric functions of the individual photonic crystal components. The spontaneous-emission rate is evaluated for a dipole emitter situated in the slab region, and oscillating at a frequency resonant with one of the modes that are localized within the slab and exponentially decaying within the photonic crystals. Both symmetric and asymmetric structures are discussed. Interesting features are predicted when the variations of the adjustable parameters are examined, including suppression and enhancement of the spontaneous rate.