Related papers: Measurement of one-photon and two-photon wavepacke…
It is conjectured that the effects of reduction, which occur with the individual wavepackets in a system of two separated though entangled packets, occur simultaneously in the center frame (properly defined) of the entangled packets.…
Real-time controls based on quantum measurements are powerful tools for various quantum protocols. However, their experimental realization have been limited by mode-mismatch between temporal mode of quadrature measurement and that heralded…
Entanglement generated by Spontaneous Parametric Down Conversion (SPDC) involves multiple, often mutually correlated degrees of freedom. These degrees of freedom are often treated independently, overlooking the intrinsic correlation between…
We test two-dimensional TPSA of biphoton light emitted via ultrafast spontaneous parametric down-conversion (SPDC) using the effect of group-velocity dispersion in optical fibres. Further, we apply this technique to demonstrate the…
We describe spontaneous parametric down-conversion experiments in which induced coherence across two coupled interferometers results in high-visibility single-photon interference. Opening additional photon channels allows "which-path"…
We experimentally demonstrate a simple method to measure the biphoton joint spectrum by mapping the spectral information onto the temporal domain using a dispersive medium. Various top-hat spectral filters are used to limit the spectral…
We investigate two-photon quantum interference in an opaque scattering medium that intrinsically supports $10^6$ transmission channels. By adaptive spatial phase-modulation of the incident wavefronts, the photons are directed at targeted…
Properties of entangled photon pairs generated in spontaneous parametric down-conversion are investigated in interference experiments. Strong energy correlations are demonstrated in a direct way. If a signal photon is detected behind a…
In this work we study the spatio-temporal correlations of photons produced by spontaneous parametric down conversion. In particular, we study how the waists of the detection and pump beams impact on the spectral bandwidth of the photons.…
The thorough characterization of entangled-photon sources is vital for their optimal use in quantum communication. However, this task is not trivial at telecommunication wavelengths. While cameras and spectrometers are well developed for…
We report experimental observations of correlated-photon statistics in the single-photon detection rate. The usual quantum interference in a two-photon polarization interferometer always accompanies a dip in the single detector counting…
Single-photon sources are a fundamental resource in quantum optics. The indistinguishability and purity of photons emitted from different sources are crucial (necessary, essential) properties for many quantum applications to ensure…
Generation of entangled photons through spontaneous parametric down-conversion (SPDC) from ultrasmall sources like thin films, metasurfaces, or nanoantennas, offers unprecedented freedom in quantum state engineering. However, as the source…
Single-photon sources (SPSs) are mainly characterized by the minimum value of their second-order coherence function, viz. their $g^{(2)}$ function. A precise measurement of $g^{(2)}$ may, however, require high time-resolution devices, in…
We present a theoretical analysis of two-photon absorption of classical and squeezed light valid when one-photon absorption to an intermediate state is either resonant or far-detuned from resonance, and in both the low and high intensity…
We use a non-perturbative theoretical approach to the parametric down-conversion (PDC) process, which generates entangled-photon field for an arbitrarily strong pump-pulse. This approach can be used to evaluate multi-point field correlation…
Frequency-entangled photons can be readily produced using parametric down-conversion. We have recently shown how such entanglement could be manipulated and measured using electro-optic phase modulators and narrow-band frequency filters,…
The development of efficient protocols for pure and mixed states preparation is challenging task. Most of the theory of quantum information applications has been developed for fully coherent or completely incoherent light. However, in many…
Path-entangled multi-photon states allow optical phase-sensing beyond the shot-noise limit, provided that an efficient parity measurement can be implemented. Realising this experimentally is technologically demanding, as it requires…
Wave-particle duality and entanglement are two fundamental characteristics of quantum mechanics. All previous works on experimental investigations in wave{particle properties of single photons (or single particles in general) show that a…