An information entropy interpretation of photon absorption by dielectric media (original) (raw)

There’s plenty of light at the bottom: statistics of photon penetration depth in random media

Scientific Reports, 2016

We propose a comprehensive statistical approach describing the penetration depth of light in random media. The presented theory exploits the concept of probability density function f(z|ρ, t) for the maximum depth reached by the photons that are eventually re-emitted from the surface of the medium at distance ρ and time t. Analytical formulas for f, for the mean maximum depth 〈z max 〉 and for the mean average depth z reached by the detected photons at the surface of a diffusive slab are derived within the framework of the diffusion approximation to the radiative transfer equation, both in the time domain and the continuous wave domain. Validation of the theory by means of comparisons with Monte Carlo simulations is also presented. The results are of interest for many research fields such as biomedical optics, advanced microscopy and disordered photonics.

Does the photon-diffusion coefficient depend on absorption?

1997

We investigate the controversy over the precise form of the photon diffusion coefficient and suggest that it is largely independent of absorption, ie, D_0= v/3μ_s^′. After presentation of the general theoretical arguments underlying this assertion, Monte Carlo simulations are performed and explicitly reveal that the absorption-independent diffusion coefficient gives better agreement with theory than the traditionally accepted photon diffusion coefficient, D_μ_a= v/3 (μ_s^′+ μ_a).

New experiments call for a continuous absorption alternative to the photon model

The Nature of Light: What are Photons? VI, 2015

A famous beam-split coincidence test of the photon model was performed with γ-rays instead of visible light. A similar test was performed to split α-rays. In both tests, coincidence rates greatly exceed chance, leading to an unquantum effect. In contradiction to quantum theory and the photon model, these new results are strong evidence of the long abandoned accumulation hypothesis, also known as the loading theory. Attention is drawn to assumptions applied to past key experiments that led to quantum mechanics. The history of the loading theory is outlined, and a few key experiment equations are derived, now free of wave-particle duality. Quantum theory usually works because there is a subtle difference between quantized and thresholded absorption.

Transmission of light in crystals with different homogeneity: using Shannon index in photonic media

Journal of The European Optical Society-rapid Publications, 2010

Light transmission in inhomogeneous photonic media is strongly influenced by the distribution of the diffractive elements in the medium. Here it is shown theoretically that, in a pillar photonic crystal structure, light transmission and homogeneity of the pillar distribution are correlated by a simple linear law once the grade of homogeneity of the photonic structure is measured by the Shannon index, widely employed in statistics, ecology and information entropy. The statistical analysis shows that the transmission of light in such media depends linearly from their homogeneity: the more is homogeneous the structure, the more is the light transmitted. With the found linear relationship it is possible to predict the transmission of light in random photonic structures. The result can be useful for the study of electron transport in solids, since the similarity with light in photonic media, but also for the engineering of scattering layers for the entrapping of light to be coupled with photovoltaic devices.

Propagation of quantum states of light through absorbing and amplifying media

Optics Communications, 2008

We describe how quantum features of light fields become modified upon propagation through absorbing and amplifying media. Both absorption and amplification add noise to a beam of light. We examine the extent to which quantum features remain after this noise is added. We also examine the question of whether certain quantum states are more robust than others against degradation due to loss. Quantum states of this sort would constitute an important resource for use in quantum information processing. We quantify this thought by determining how the integration time required to achieve a specified signal-to-noise ratio increases in the presence of transmission losses. We find that under certain circumstances the required integration time increases more rapidly with transmission loss for measurement strategies based on coincidence detection of entangled photons than for strategies based on the properties of squeezed light.

Quantum entropy and polarization measurements of the two-photon system

Physical Review A

We consider the bipartite state of a two-photon polarization system and obtain the exact analytical expression for the von Neumann entropy in the particular case of a 5-parameter polarization density matrix. We investigate and graphically illustrate the dependence of the entropy on these five parameters, in particular, the existence of exotic, transition from exotic to non-exotic, and non-exotic states, where the quantum conditional entropy is negative, both positive and negative, and positive, respectively. We study the "cooling" or "heating" effect that follows from the reduced density of photon 2 when a measurement is performed on photon 1.

Dissipation and decoherence in photon interferometry

Journal of Optics B: Quantum and Semiclassical Optics, 2002

The propagation of polarized photons in optical media can be effectively modeled by means of quantum dynamical semigroups. These generalized time evolutions consistently describe phenomena leading to loss of phase coherence and dissipation originating from the interaction with a large, external environment. High sensitive experiments in the laboratory can provide stringent bounds on the fundamental energy scale that characterizes these non-standard effects.

Photon entanglement entropy as a probe of many-body correlations and fluctuations

The Journal of Chemical Physics

Recent theoretical and experiments have explored the use of entangled photons as a spectroscopic probe of material systems. We develop here a theoretical description for entropy production in the scattering of an entangled biphoton state within an optical cavity. We develop this using perturbation theory by expanding the biphoton scattering matrix in terms of single-photon terms in which we introduce the photonphoton interaction via a complex coupling constant, ξ. We show that the von Neumann entropy provides a succinct measure of this interaction. We then develop a microscopic model and show that in the limit of fast fluctuations, the entanglement entropy vanishes whereas in the limit the coupling is homogeneous broadened, the entanglement entropy depends upon the magnitude of the fluctuations and reaches a maximum. S (2) (ω 1 , ω 2 ; ω 1 , ω 2)F(ω 1 , ω 2)B † (ω 1)B † (ω 2)|0

Competition between one- and two-photon absorption processes

Journal of Physics A: Mathematical and General, 1997

We obtain an exact analytical solution to the master equation for the diagonal density matrix elements of the one-mode quantized field, when both one-and two-photon absorption processes are present. Explicit expressions for the time dependences of the factorial moments are found. The special cases of the initial Fock's, binomial, negative binomial, thermal, and coherent states, as well as of their even/odd counterparts are considered in detail. The existence of the universal time-dependent distribution of initially highly excited states is discovered, and simple explicit expressions are given for some specific values of parameters. This distribution holds for times exceeding the transition time of the order of (D 2 n 0 ) −1 , D 2 , n 0 being the twophoton absorption coefficient and the initial mean photon number, respectively. The transition time from any initial state to the ground state is shown to be finite even for highly excited states, provided that D 2 = 0. Although the final stage of evolution is characterized by the sub-Poissonian statistics for any initial state, Mandel's parameter is shown to be very sensitive to small differences in high-order initial factorial moments at the intermediate stage. † On leave from: