The statistical properties of fluorescent light from a single two-level atom driven by nonclassical light beams that exhibit antibunching and squeezing are discussed in the weak-field limit. The fields produced in intracavity second-harmonic generation and those produced by superposing the light from a degenerate parametric oscillator with a coherent field are considered to be the models of nonclassical light beams. These fields can be described in terms of real Gaussian random processes with nonzero mean coherent components. Analytical expressions for the fluorescent light intensity, the second-order intensity correlation function, and the variance of the photon number in the steady state are obtained. The effects of driving-field correlations, detuning, and other parameters characterizing the atom-field interaction on the statistics of scattered light are investigated. It is found that for a certain range of parameters the second-order intensity correlation function may vanish at nonzero times. Under certain other circumstances the antibunching of the fluorescent photons is enhanced. These and other interesting features that appear in the scattered light are discussed.
The statistical properties of fluorescent light from a single two-level atom driven by nonclassical light beams that exhibit antibunching and squeezing are discussed in the weak-field limit. The fields produced in intracavity second-harmonic generation and those produced by superposing the light from a degenerate parametric oscillator with a coherent field are considered to be the models of nonclassical light beams. These fields can be described in terms of real Gaussian random processes with nonzero mean coherent components. Analytical expressions for the fluorescent light intensity, the second-order intensity correlation function, and the variance of the photon number in the steady state are obtained. The effects of driving-field correlations, detuning, and other parameters characterizing the atom-field interaction on the statistics of scattered light are investigated. It is found that for a certain range of parameters the second-order intensity correlation function may vanish at nonzero times. Under certain other circumstances the antibunching of the fluorescent photons is enhanced. These and other interesting features that appear in the scattered light are discussed.
Statistical properties of fluorescent light from a single two-level atom driven by a beam of antibunched light are discussed in the weak field limit. Fields generated by realistic open systems with pumping and dissipation are chosen to be the models for antibunched light. As examples, we consider fields produced in intracavity second harmonic generation and in the homodyned degenerate parametric oscillator. These fields can be described in terms of real Gaussian random processes with coherent components. Analytical expressions for fluorescent light intensity and second order intensity correlation function in the steady state are derived. Effects of driving field correlations, detuning, and parameters characterizing the driving field on the statistics of scattered light are investigated. It is found that over a certain range of parameters characterizing the driving field the second order intensity correlation function may vanish at non-zero time. These and other interesting features will be discussed.
Resonance fluorescence from a single two-level atom driven by a beam of squeezed light is studied in the weak field limit. We consider the situation where the atom is coupled to the ordinary vacuum and only a few field modes corresponding to the driving field are squeezed. The field produced by the degenerate optical parametric oscillator is used as the driving field. This driving field can be described in terms of two real independent Gaussian processes. Heisenberg equations of motion are solved in the steady-state, and analytic expressions for the fluorescent light intensity and the spectrum of fluorescent light are derived. We also consider photon statistics of fluorescent light. In particular, squeezing, antibunching, and sub-Poissonian statistics of fluorescent photons are discussed and analytic expressions for the quadrature variance and the two-time intensity correlation function are presented. Contrary to the case of coherent excitation the second-order intensity correlation function does not factorize.
Resonance fluorescence from a single two-level atom driven by a beam of squeezed light is studied in the weak-field limit. We consider the situation where the atom is coupled to the ordinary vacuum and only a few field modes corresponding to the driving field are squeezed. The field produced by the degenerate optical parametric oscillator is used as the driving field. Heisenberg equations of motion are solved in the steady-state and analytic expressions for the fluorescent-light intensity and the spectrum of fluorescent light are derived. We also consider photon statistics of fluorescent light. In particular, squeezing, antibunching, and sub-Poissonian statistics of fluorescent photons are discussed, and analytic expressions for the quadrature variance and the two-time intensity correlation function are presented. Contrary to the case of coherent excitation, the second-order intensity correlation function does not factorize. This and other differences are discussed, and curves are presented to illustrate the behavior of various quantities. We also present results for thermal excitation of the atom.
We consider a single two-level atom in an optical cavity, in which the system is driven by a coherent driving field. In the bad-cavity limit, when the cavity loss rate is taken to be large compared to the atomic decay rate and atom-field coupling, the cavity field can be adiabatically eliminated from the equations of motion for the atomic operators. The main effect of the cavity in this limit is the enhancement of spontaneous emission into the cavity mode. For this model, the second-order intensity correlation function g(2)() has been shown to exhibit photon antibunching, sub-Poissonian photon number distributions, and other nonclassical effects.1 In this paper, analytic results are presented for g(2)() for both the transmitted and fluorescent light fields when broadband squeezed light is injected into the cavity. Effects of the squeezing on nonclassical behavior is examined.
We consider a two-level atom driven by an ideal degenerate optical parametric oscillator. For squeezing bandwidths of the order of the natural width $\ensuremath{\gamma},$ and smaller, we report remarkable spectral profiles for the scattered light. We also consider a system where the atom is driven by arbitrarily correlated light of arbitrary bandwidth. Employing analytic and numerical solutions, we find different spectral features depending on the classical or nonclassical nature of the driving field. The spectral linewidth can be both subnatural and narrower than the incident field linewidth, an effect that does not require nonclassical light. However, nonclassical light is essential for the appearance of a narrow hole at line center. It is a unique signature of the quantum nature of the field, and for ideal squeezing, the fluorescence at line center vanishes.
We consider an optical cavity containing a single two-level atom driven on resonance by an external laser source.1 We focus on the limit of weak excitation where the dynamic response of this system is governed by just three parameters: the atom-field coupling constant g, spontaneous emission rate γ for the atom, and cavity decay rate κ. The statistics of the transmitted light are analyzed as a function of g, γ, and κ, in terms of the second-order correlation function g(2)(τ), and the quadrature variances measured in a homodyne detection scheme. Squeezing and photon antibunching exist over a wide range of parameters. For γ ~ κ, the system can exhibit an oscillatory response, even when the mean intracavity photon number is much less than unity.2 The oscillations can be understood in terms of the coupling between the free atom-field eigenstates |0,−>, |0,+>, and |1,−>. The oscillation frequency is determined by the energy level splitting produced between the degenerate one-quantum states |0,+> and |1,−> by the atom-field interaction. The second-order correlation function can exhibit a novel nonclassical effect, where, for g(2)(0) ≠ 0, at some finite delay τ0, the correlation function dips exactly to zero—g(2)(τ0) = 0.