Optical pulses are used to quantum mechanically entangle two diamonds several centimeters apart.

Single photons are a vital resource for optical quantum information processing. Efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of processing primitives have been implemented using nondeterministic combined with heralding and/or postselection. Unfortunately, even eight photons, the data rates already so low as to make most experiments impracticable. It is well known that memories, capable storing until they needed, potential...

We investigate the use of correlated photon pair sources for improved quantum-level detection a target in presence noise background. Photon pairs are generated by spontaneous four-wave mixing, one from each (the herald) is measured locally while other signal) sent to illuminate target. Following diffuse reflection target, signal photons detected receiver and non-classical timing correlations between herald configurable background source. Quantum source can be used provide an enhanced...

We report the storage and retrieval of single photons, via a quantum memory, in optical phonons room-temperature bulk diamond. The THz-bandwidth heralded photons are generated by spontaneous parametric down-conversion mapped to Raman transition, stored for variable delay, released on demand. second-order correlation memory output is g((2))(0)=0.65±0.07, demonstrating preservation nonclassical photon statistics throughout retrieval. low noise, high speed broadly tunable; it therefore promises...

Broadband quantum memories, used as temporal multiplexers, are a key component in photonic information processing, they make repeat-until-success strategies scalable. We demonstrate prototype system, operating on-demand, by interfacing warm vapour, high time-bandwidth-product Raman memory with travelling wave spontaneous parametric down-conversion source. store single photons and observe clear influence of the input photon statistics on retrieved light, which we find currently to be limited...

Quantum memories are vital to the scalability of photonic quantum information processing (PQIP), since storage photons enables repeat-until-success strategies. On other hand key element all PQIP architectures is beam splitter, which allows coherently couple optical modes. Here we show how combine these crucial functionalities by addressing a Raman memory with multiple control pulses. The result coherent device an extremely large time-bandwidth product, that functions as array dynamically...

Optical quantum memories are vital for the scalability of future technologies, enabling long-distance secure communication and local synchronization components. We demonstrate a THz-bandwidth memory light using optical phonon modes room temperature diamond. This large bandwidth makes compatible with down-conversion-type photon sources. that four-wave mixing noise in this system is suppressed by material dispersion. The resulting floor just 7×10(-3) photons per pulse, which establishes...

In this work we investigate quantum-enhanced target detection in the presence of large background noise using multidimensional quantum correlations between photon pairs generated through spontaneous parametric down-conversion. Until now similar experiments have only utilized one pairs' many degrees freedom such as temporal and number correlations. Here, both spectral achieved over an order magnitude reduction to turn significant data acquisition time when compared utilizing modes. We believe...

In order to enhance LIDAR performance metrics such as target detection sensitivity, noise resilience and ranging accuracy, we exploit the strong temporal correlation within photon pairs generated in continuous-wave pumped semiconductor waveguides. The enhancement attained through use of non-classical sources is measured compared a corresponding scheme based on simple photon-counting detection. performances both schemes are quantified by estimation uncertainty Fisher information probe...

The photonic temporal degree of freedom is one the most promising platforms for quantum communication over fiber networks and free-space channels. In particular, time-bin states photons are robust to environmental disturbances, support high-rate communication, can be used in high-dimensional schemes. However, detection remains a challenging task, particularly case that superposition different time bins. Here, we experimentally demonstrate feasibility picosecond light, known as ultrafast...

Abstract We show a simple yet effective method that can be used to characterize the per pixel quantum efficiency and temporal resolution of single photon event camera for imaging applications. Utilizing pairs generated through spontaneous parametric down-conversion, detection each pixel, system, are extracted coincidence measurements. use this evaluate TPX3CAM, with appended image intensifier, measure an average $$7.4\pm 2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">...

As first demonstrated by Hanbury Brown and Twiss, it is possible to observe interference between independent light sources measuring correlations in their intensities rather than amplitudes. In this work, we apply concept of intensity interferometry holography. We combine a signal beam with reference measure cross-correlations using time-tagging single-photon camera. These reveal an pattern from which reconstruct the wavefront both phase. demonstrate principle classical quantum light,...

Light-field microscopy (LFM) extracts volumetric data from a specimen by simultaneously capturing the positional and angular information of light rays emanating sample. While conventional LFM requires compromise between depth field (DOF) resolution, this work introduces quantum approach to eliminate harnessing position-momentum entanglement photon pairs. Compared at same can yield up tenfold improvement in DOF. This illustrates power utilizing multidimensional hopefully will inspire further...

Controlling the properties of single photons is essential for a wide array emerging optical quantum technologies spanning sensing, computing, and communications. Essential components these include photon sources, memories, waveguides, detectors. The ideal spectral operating parameters (wavelength bandwidth) are rarely similar; thus, frequency conversion control key enabling steps component hybridization. Here we perform signal processing by coherently manipulating their spectra via modified...

Abstract Underwater quantum communication has recently been explored using polarization and orbital angular momentum (OAM). Here, we show that spatially structured modes, e.g., a coherent superposition of beams carrying both OAM, can also be used for underwater cryptography. We use the degree freedom to investigate impact channel length on key rates applications. The proves difficult environment establishing as optical turbulence results in significant beam wandering distortions. However,...

We examine the propagation of optical beams possessing different polarization states and spatial modes through Ottawa River in Canada. A Shack-Hartmann wavefront sensor is used to record distorted beam's wavefront. The turbulence underwater channel analysed, associated Zernike coefficients are obtained real-time. Finally, we explore feasibility transmitting as well for applications quantum cryptography.

Determining a beam's full trajectory requires tracking both its position and momentum (angular) information. However, the product of uncertainty in simultaneous measurement two parameters is bound by Heisenberg limit (HUL). In this work, we present proof-of-principle demonstration quantum-enhanced beam technique, leveraging inherent entanglement between photons produced via spontaneous parametric down-conversion (SPDC). We show that quantum can be exploited to achieve accuracy beyond HUL...

Hyperentanglement, which refers to entanglement across more than one degree of freedom (DoF), is a valuable resource in photonic quantum information technology. However, the lack efficient characterization schemes hinders its quantitative study and application potential. Here, we present rapid spatial-polarization hyperentangled biphoton state produced from spontaneous parametric down-conversion. We first demonstrate certification hyperentanglement dimensionality with cumulative acquisition...

The unusual features of quantum mechanics are enabling the development technologies not possible with classical physics. These devices utilize nonclassical phenomena in states atoms, ions, and solid-state media as basis for many prototypes. Here we investigate molecular a distinct alternative. We demonstrate memory light based on storing photons vibrations hydrogen molecules. THz-bandwidth is used to store 100-fs pulses durations up ~1 ns, ~10(4) operational time bins. results promise...

Quantum key distribution is on the verge of real world applications, where perfectly secure information can be distributed among multiple parties. Several quantum cryptographic protocols have been theoretically proposed and independently realized in different experimental conditions. Here, we develop an platform based high-dimensional orbital angular momentum states single photons that enables implementation with a apparatus. Our versatile approach allows us to experimentally survey classes...

In this work we demonstrate spectral-temporal correlation measurements of the Hong-Ou-Mandel (HOM) interference effect with use a spectrometer based on photon-counting camera. This setup allows us to take, within seconds, spectral temporal entangled photon sources sub-nanometer resolution and nanosecond timing resolution. Through post processing, can observe HOM behaviour for any number filters shape width at wavelength over observable range. Our also offers great versatility in that it is...