Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:quant-ph/0608003

Experimental setup for measuring the speed of interference

Masanori Sato

Published Jul 31, 2006• 0 citations
arXivHTMLPDF

Abstract

The transient phenomena of the Mach-Zender interferometer are discussed. To test the non-locality hypothesis, a single mode laser with a large coherence length is used. The behavior of a photon and its wave packets in the paths of the interferometer are discussed. Coherent photons have wave packets that overlap, thus their interference pattern is influenced by the overlap of the wave packets of other photons in transient phenomena. The proposed transient light-interference experiment will provide experimental data testing the non-locality hypothesis.

Related papers

Discussion on the speed of interference: Transient phenomena in delayed-choice experiments

Masanori Sato

Signaling by a delayed-choice experimental setup was discussed in the previous report [M. Sato, quant-ph/0409059]. In this report, the speed of the interference pattern generation in Wheeler's delayed-choice experiment is discussed, and a feasible experimental proposal is provided. The duality of locality and nonlocality obviously appears in the de Broglie-Bohm picture. Locality corresponds to the particle property and nonlocality corresponds to the wave property. The interference of a photon can be recognized using the de Broglie-Bohm picture. A photon moves at the speed of light, however the speed of the interference pattern formation, which is conducted by a quantum potential, is not seen to be restricted by the speed of light.

•Jul 31, 2006•0 citations

Interference between non-overlapping wave-packets of a single photon

Nicklas Ohlsson, R.K. Mohan, Stefan Kröll +1 more

Summary form only given. Consider an experiment where a single photon is split into two wave-packets by a beam splitter and where the two wave packets are made to overlap in a specific region in space. If the two wave-packets arrive at the same time, an interference pattern can be recorded by a classical detector such as a photographic plate. If however, the difference in arrival time between the two wave-packets is made to be larger than the coherence time of the wave packets, the interference pattern, as recorded by the detector, will disappear. It has been argued that if the classical detector is replaced by a material that can remember the phase of the electromagnetic field, i.e. a material with a long homogeneous dephasing time, it would be possible to record the interference between the two wave-packets even if the time difference between them is much larger than the coherence time. We denote this single-photon self-interference. The interference pattern would take the form of a frequency dependent population grating in the material and could be detected by diffracting a light pulse on this grating. The delayed single-photon self-interference experiment has several unique features. It is a four-wave mixing experiment where the two first pulses share a total of only one photon. Thus interaction between these two pulses and the material, normally considered as a nonlinear multiphoton process, is here carried out by a single photon. We have performed experiments with multiphoton excitation pulses and extrapolated the data to the single photon level. These experiments support the conclusion from the theoretical calculations that delayed single-photon self-interference could be observed.

Conference on Lasers and Electro-Optics•Aug 29, 2005•0 citations

Revisiting self-interference in double-slit experiments

S. Kim, Byoung Seung HAM

Over the past several decades, single photon-based path interference in double-slit experiment has been well demonstrated for the particle nature of photons satisfying complementarity theory, where the quantum mechanical interpretation of the single photon interference fringe is given by Born rule for complex amplitudes in measurements. Unlike most conventional methods using entangled photon pairs, here, a classical coherent light source is directly applied for the proof of the same self-interference phenomenon. Instead of double slits, we use a Mach-Zehnder interferometer as usual, where the resulting self-interference fringe of coherent single photons is exactly the same as that of the coherent photon ensemble of the laser, demonstrating that the classical coherence based on the wave nature is rooted in the single photon self-interference. This unexpected result seems to contradict our common understanding of decoherence phenomena caused by multi-wave interference among bandwidth distributed photons in coherence optics.

•Apr 16, 2021•1 citation

Observation of the First-Order Interference Fringes Beyond Coherence Length Employing Commercial Continuous-wave Multi-mode Laser Diode: A Sight of Two-photon Interference

Hongmin Liu

We report an experiment of observation of classical double-slit interference fringes of two-photon interference. In the experiment, a commercial continuous-wave multi-mode F-P laser diode without either mode-locked or frequency-locked is used as the light source, the density of photons is far more than the single-photon level, and the path difference of the long and short paths is far more than the longitudinal coherence length of the laser diode. The temporal stable and clearly visible spatial-distributed pattern, i.e. first-order interference fringes, was observed .Contradict to the prediction of single-photon interference mechanism, the interference happened far beyond the coherence length, the occurrence possibility and time duration of the interference fringes decrease with the reduction of mode number of the LD, and the time difference between the fringes disappearance and the light vanish is equal to the time difference of the two paths. After discussion, we came to the conclusion that the observed phenomena can be understood in time-resolved two-photon interference mechanism. We reveal a new method to perform two-photon first-order interference, and this help to understand the nature of two-photon interference and also can be useful for quantum information science.

arXiv:2402.15041•Feb 23, 2024•0 citations

Analysis of single-photon self-interference in Young’s double-slit experiments

Jau Tang, Zhibin Hu

For centuries Young’s double-slit interference continues to be a hot discussion subject about whether light is waves or particles. This work unravels the self-interference parados, and sheds light on such a concept that assumes a photon can split, self-interfere, and recombine. This work elucidates how coherent photons from a laser source could produce a double-slit interference pattern without the hypothesis of unphysical splitting and recombination of a single photon. Unlike the conventional single wave-function description for the whole ensemble of particles, we develop a pilot-wave trajectory approach to track every photon’s wave-packet propagation and calculate the evolution of the interference intensity in time. We demonstrate how wave packets and phase coherence affect the interference pattern. To resolve the century-old self-interference paradox, we show that such an hypothesis is unnecessary, and the illusion is due to the long coherence length of laser photons and overlaps of delocalized light wave packets.

Results in Optics•Aug 2, 2022•7 citations

Spatial coherence of light in the two-photon state

E. J. S. Fonseca, Carlos Henrique Monken, N. Padua +1 more

Summary form only given. We present experimental results of the Young's double-slit interference pattern of light in the two-photon state. By doing Young's interference experiments with the output light of a Hong-Ou-Mandel (H-O-M) interferometer, we are able to study the spatial coherence properties of the light in the two photon state (two photons in the same wave packet).

Conference on Lasers and Electro-Optics•Nov 27, 2002•0 citations
The transient phenomena of the Mach-Zender interferometer are discussed. To test the non-locality hypothesis, a single mode laser with a large coherence length is used. The behavior of a photon and its wave packets in the paths of the interferometer are discussed. Coherent photons have wave packets that overlap, thus their interference pattern is influenced by the overlap of the wave packets of other photons in transient phenomena. The proposed transient light-interference experiment will provide experimental data testing the non-locality hypothesis.
Signaling by a delayed-choice experimental setup was discussed in the previous report [M. Sato, quant-ph/0409059]. In this report, the speed of the interference pattern generation in Wheeler's delayed-choice experiment is discussed, and a feasible experimental proposal is provided. The duality of locality and nonlocality obviously appears in the de Broglie-Bohm picture. Locality corresponds to the particle property and nonlocality corresponds to the wave property. The interference of a photon can be recognized using the de Broglie-Bohm picture. A photon moves at the speed of light, however the speed of the interference pattern formation, which is conducted by a quantum potential, is not seen to be restricted by the speed of light.
Summary form only given. Consider an experiment where a single photon is split into two wave-packets by a beam splitter and where the two wave packets are made to overlap in a specific region in space. If the two wave-packets arrive at the same time, an interference pattern can be recorded by a classical detector such as a photographic plate. If however, the difference in arrival time between the two wave-packets is made to be larger than the coherence time of the wave packets, the interference pattern, as recorded by the detector, will disappear. It has been argued that if the classical detector is replaced by a material that can remember the phase of the electromagnetic field, i.e. a material with a long homogeneous dephasing time, it would be possible to record the interference between the two wave-packets even if the time difference between them is much larger than the coherence time. We denote this single-photon self-interference. The interference pattern would take the form of a frequency dependent population grating in the material and could be detected by diffracting a light pulse on this grating. The delayed single-photon self-interference experiment has several unique features. It is a four-wave mixing experiment where the two first pulses share a total of only one photon. Thus interaction between these two pulses and the material, normally considered as a nonlinear multiphoton process, is here carried out by a single photon. We have performed experiments with multiphoton excitation pulses and extrapolated the data to the single photon level. These experiments support the conclusion from the theoretical calculations that delayed single-photon self-interference could be observed.
Over the past several decades, single photon-based path interference in double-slit experiment has been well demonstrated for the particle nature of photons satisfying complementarity theory, where the quantum mechanical interpretation of the single photon interference fringe is given by Born rule for complex amplitudes in measurements. Unlike most conventional methods using entangled photon pairs, here, a classical coherent light source is directly applied for the proof of the same self-interference phenomenon. Instead of double slits, we use a Mach-Zehnder interferometer as usual, where the resulting self-interference fringe of coherent single photons is exactly the same as that of the coherent photon ensemble of the laser, demonstrating that the classical coherence based on the wave nature is rooted in the single photon self-interference. This unexpected result seems to contradict our common understanding of decoherence phenomena caused by multi-wave interference among bandwidth distributed photons in coherence optics.
We report an experiment of observation of classical double-slit interference fringes of two-photon interference. In the experiment, a commercial continuous-wave multi-mode F-P laser diode without either mode-locked or frequency-locked is used as the light source, the density of photons is far more than the single-photon level, and the path difference of the long and short paths is far more than the longitudinal coherence length of the laser diode. The temporal stable and clearly visible spatial-distributed pattern, i.e. first-order interference fringes, was observed .Contradict to the prediction of single-photon interference mechanism, the interference happened far beyond the coherence length, the occurrence possibility and time duration of the interference fringes decrease with the reduction of mode number of the LD, and the time difference between the fringes disappearance and the light vanish is equal to the time difference of the two paths. After discussion, we came to the conclusion that the observed phenomena can be understood in time-resolved two-photon interference mechanism. We reveal a new method to perform two-photon first-order interference, and this help to understand the nature of two-photon interference and also can be useful for quantum information science.
For centuries Young’s double-slit interference continues to be a hot discussion subject about whether light is waves or particles. This work unravels the self-interference parados, and sheds light on such a concept that assumes a photon can split, self-interfere, and recombine. This work elucidates how coherent photons from a laser source could produce a double-slit interference pattern without the hypothesis of unphysical splitting and recombination of a single photon. Unlike the conventional single wave-function description for the whole ensemble of particles, we develop a pilot-wave trajectory approach to track every photon’s wave-packet propagation and calculate the evolution of the interference intensity in time. We demonstrate how wave packets and phase coherence affect the interference pattern. To resolve the century-old self-interference paradox, we show that such an hypothesis is unnecessary, and the illusion is due to the long coherence length of laser photons and overlaps of delocalized light wave packets.