Ballistic photon

About: Ballistic photon is a research topic. Over the lifetime, 568 publications have been published within this topic receiving 21295 citations.

Correlation between Photons in two Coherent Beams of Light

Abstract: Classical interferometry works by detecting correlations in the phases of two waves. In Nature in 1956, R. Hanbury-Brown and R. Q. Twiss demonstrated another technique that probes quantum-mechanical correlations in the electromagnetic field. Splitting an incoherent light beam, they found that photon detections in the two daughter beams were correlated: the photons were bunching together. This corresponds to a correlation in the intensity of light in the two beams, which Hanbury-Brown and Twiss suggested could be used to infer the angular size of distant stars. Physicists now rely on the effect to probe the quantum character of complex light sources. [Obituary of Robert Hanbury Brown: Nature 416, 34 (2002)]

Indistinguishable photons from a single-photon device

Abstract: Single-photon sources have recently been demonstrated using a variety of devices, including molecules1,2,3, mesoscopic quantum wells4, colour centres5, trapped ions6 and semiconductor quantum dots7,8,9,10,11. Compared with a Poisson-distributed source of the same intensity, these sources rarely emit two or more photons in the same pulse. Numerous applications for single-photon sources have been proposed in the field of quantum information, but most—including linear-optical quantum computation12—also require consecutive photons to have identical wave packets. For a source based on a single quantum emitter, the emitter must therefore be excited in a rapid or deterministic way, and interact little with its surrounding environment. Here we test the indistinguishability of photons emitted by a semiconductor quantum dot in a microcavity through a Hong–Ou–Mandel-type two-photon interference experiment13,14. We find that consecutive photons are largely indistinguishable, with a mean wave-packet overlap as large as 0.81, making this source useful in a variety of experiments in quantum optics and quantum information.

Biomedical Optics: Principles and Imaging

Abstract: Preface. 1. INTRODUCTION. 1.1.Motivation for optical imaging. 1.2.General behavior of light in biological tissue. 1.3.Basic physics of light-matter interaction. 1.4.Absorption and its biological origins. 1.5.Scattering and its biological origins. 1.6.Polarization and its biological origins. 1.7.Fluorescence and its biological origins. 1.8.Image characterization. 1.9.References. 1.10.Further readings. 1.11.Problems. 2. RAYLEIGH THEORY AND MIE THEORY FOR A SINGLE SCATTERER. 2.1.Introduction. 2.2.Summary of the Rayleigh theory. 2.3.Numerical example of the Rayleigh theory. 2.4.Summary of the Mie theory. 2.5.Numerical example of the Mie theory. 2.6.Appendix 2.A. Derivation of the Rayleigh theory. 2.7.Appendix 2.B. Derivation of the Mie theory. 2.8.References. 2.9.Further readings. 2.10.Problems. 3. MONTE CARLO MODELING OF PHOTON TRANSPORT IN BIOLOGICAL TISSUE. 3.1.Introduction. 3.2.Monte Carlo method. 3.3.Definition of problem. 3.4.Propagation of photons. 3.5.Physical quantities. 3.6.Computational examples. 3.7.Appendix 3.A. Summary of MCML. 3.8.Appendix 3.B. Probability density function. 3.9.References. 3.10.Further readings. 3.11.Problems. 4. CONVOLUTION FOR BROADBEAM RESPONSES. 4.1.Introduction. 4.2.General formulation of convolution. 4.3.Convolution over a Gaussian beam. 4.4.Convolution over a top-hat beam. 4.5.Numerical solution to convolution. 4.6.Computational examples. 4.7.Appendix 4.A. Summary of CONV. 4.8.References. 4.9.Further readings. 4.10.Problems. 5. RADIATIVE TRANSFER EQUATION AND DIFFUSION THEORY. 5.1.Introduction. 5.2.Definitions of physical quantities. 5.3.Derivation of the radiative transport equation. 5.4.Diffusion theory. 5.5.Boundary conditions. 5.6.Diffuse reflectance. 5.7.Photon propagation regimes. 5.8.References. 5.9.Further readings. 5.10.Problems. 6. HYBRID MODEL OF MONTE CARLO METHOD AND DIFFUSION THEORY. 6.1.Introduction. 6.2.Definition of problem. 6.3.Diffusion theory. 6.4.Hybrid model. 6.5.Numerical computation. 6.6.Computational examples. 6.7.References. 6.8.Further readings. 6.9.Problems. 7. SENSING OF OPTICAL PROPERTIES AND SPECTROSCOPY. 7.1.Introduction. 7.2.Collimated transmission method. 7.3.Spectrophotometry. 7.4.Oblique-incidence reflectometry. 7.5.White-light spectroscopy. 7.6.Time-resolved measurement. 7.7.Fluorescence spectroscopy. 7.8.Fluorescence modeling. 7.9.References. 7.10.Further readings. 7.11.Problems. 8. BALLISTIC IMAGING AND MICROSCOPY. 8.1.Introduction. 8.2.Characteristics of ballistic light. 8.3.Time-gated imaging. 8.4.Spatial-frequency filtered imaging. 8.5.Polarization-difference imaging. 8.6.Coherence-gated holographic imaging. 8.7.Optical heterodyne imaging. 8.8.Radon transformation and computed tomography. 8.9.Confocal microscopy. 8.10.Two-photon microscopy. 8.11.Appendix 8.A. Holography. 8.12.References. 8.13.Further readings. 8.14.Problems. 9. OPTICAL COHERENCE TOMOGRAPHY. 9.1.Introduction. 9.2.Michelson interferometry. 9.3.Coherence length and coherence time. 9.4.Time-domain OCT. 9.5.Fourier-domain rapid scanning optical delay line. 9.6.Fourier-domain OCT. 9.7.Doppler OCT. 9.8.Group velocity dispersion. 9.9.Monte Carlo modeling of OCT. 9.10.References. 9.11.Further readings. 9.12.Problems. 10. MUELLER OPTICAL COHERENCE TOMOGRAPHY. 10.1.Introduction. 10.2.Mueller calculus versus Jones calculus. 10.3.Polarization state. 10.4.Stokes vector. 10.5.Mueller matrix. 10.6.Mueller matrices for a rotator, a polarizer, and a retarder. 10.7.Measurement of Mueller matrix. 10.8.Jones vector. 10.9.Jones matrix. 10.10.Jones matrices for a rotator, a polarizer, and a retarder. 10.11.Eigenvectors and eigenvalues of Jones matrix. 10.12.Conversion from Jones calculus to Mueller calculus. 10.13.Degree of polarization in OCT. 10.14.Serial Mueller OCT. 10.15.Parallel Mueller OCT. 10.16.References. 10.17.Further readings. 10.18.Problems. 11. DIFFUSE OPTICAL TOMOGRAPHY. 11.1.Introduction. 11.2.Modes of diffuse optical tomography. 11.3.Time-domain system. 11.4.Direct-current system. 11.5.Frequency-domain system. 11.6.Frequency-domain theory: basics. 11.7.Frequency-domain theory: linear image reconstruction. 11.8.Frequency-domain theory: general image reconstruction. 11.9.Appendix 11.A. ART and SIRT. 11.10.References. 11.11.Further readings. 11.12.Problems. 12. PHOTOACOUSTIC TOMOGRAPHY. 12.1.Introduction. 12.2.Motivation for photoacoustic tomography. 12.3.Initial photoacoustic pressure. 12.4.General photoacoustic equation. 12.5.General forward solution. 12.6.Delta-pulse excitation of a slab. 12.7.Delta-pulse excitation of a sphere. 12.8.Finite-duration pulse excitation of a thin slab. 12.9.Finite-duration pulse excitation of a small sphere. 12.10.Dark-field confocal photoacoustic microscopy. 12.11.Synthetic aperture image reconstruction. 12.12.General image reconstruction. 12.13.Appendix 12.A. Derivation of acoustic wave equation. 12.14.Appendix 12.B. Green's function approach. 12.15.References. 12.16.Further readings. 12.17.Problems. 13. ULTRASOUND-MODULATED OPTICAL TOMOGRAPHY. 13.1.Introduction. 13.2.Mechanisms of ultrasonic modulation of coherent light. 13.3.Time-resolved frequency-swept UOT. 13.4.Frequency-swept UOT with parallel-speckle detection. 13.5.Ultrasonically modulated virtual optical source. 13.6.Reconstruction-based UOT. 13.7.UOT with Fabry-Perot interferometry. Problems. Reading. Furhter Reading. APPENDIX A. DEFINITIONS OF OPTICAL PROPERTIES. APPENDIX B. List of Acronyms. Index.

Single photons on demand from a single molecule at room temperature

Abstract: The generation of non-classical states of light is of fundamental scientific and technological interest. For example, 'squeezed' states enable measurements to be performed at lower noise levels than possible using classical light. Deterministic (or triggered) single-photon sources exhibit non-classical behaviour in that they emit, with a high degree of certainty, just one photon at a user-specified time. (In contrast, a classical source such as an attenuated pulsed laser emits photons according to Poisson statistics.) A deterministic source of single photons could find applications in quantum information processing, quantum cryptography and certain quantum computation problems. Here we realize a controllable source of single photons using optical pumping of a single molecule in a solid. Triggered single photons are produced at a high rate, whereas the probability of simultaneous emission of two photons is nearly zero--a useful property for secure quantum cryptography. Our approach is characterized by simplicity, room temperature operation and improved performance compared to other triggered sources of single photons.