A tomographic measurement is a ubiquitous tool for estimating the properties of quantum states, and its application known as state tomography (QST). The process involves manipulating single photons in sequence projective measurements, often to construct density matrix from which other information can be inferred, laborious it complex. Here we unravel steps QST outline how may demonstrated fast simple manner with intense (classical) light. We use scalar beams time reversal approach simulate...

The global quantum network requires the distribution of entangled states over long distances, with substantial advances already demonstrated using polarization. While Hilbert spaces higher dimensionality, e.g., spatial modes light, allow information capacity per photon, such mode entanglement transport custom multimode fiber and is limited by decoherence-induced coupling. Here, we circumvent this transporting multidimensional down conventional single-mode (SMF). By entangling spin-orbit...

We demonstrate a different scheme to perform optical sectioning of sample based on the concept induced coherence [Zou et al., Phys. Rev. Lett. 67, 318 (1991)]. This can be viewed as type tomography where varying reflectivity along direction propagation an beam translates into changes degree first-order between two beams. As practical advantage allows probing with one wavelength and measuring photons another wavelength. In bio-imaging scenario, this would result in deeper penetration because...

Coherence and correlations represent two related properties of a compound system. The system can be, for instance, the polarization photon, which forms part polarization-entangled two-photon state, or spatial shape coherent beam, where each mode bears different polarizations. Whereas local unitary transformation does not affect its coherence, global transformations modifying both surroundings enhance transforming mutual into coherence. question naturally arises what is best measure that...

We demonstrate the direct generation of visible vortex beams at 640 nm and 607 by employing an off-axis pumping scheme in a diode end-pumped Pr3+:YLF laser. A detailed numerical analysis, based on coherent superposition Hermite-Gaussian modes with different amplitudes phases, is perfectly consistent experimentally observed lasing modes. The maximum output powers have been measured to be 808 mW 211 pump power 3.16 W, for wavelengths nm, respectively. also handedness control generated beam....

One of the most captivating properties diffraction-free optical fields is their ability to reconstruct upon propagation in presence an obstacle both, classically and quantum regime. Here we demonstrate that local entanglement, or non-separability, between spatial polarisation degrees freedom also experience self-healing. We measured quantified degree non-separability two when propagating behind various obstructions, which were generated digitally. Experimental results show even though...

Abstract Traditional ghost imaging requires correlated but spatially separated photons and has been observed in many physical situations, spanning both the quantum classical regimes. Here we observe a new system—a system based on entanglement swapping, key feature of network. We detail how exact form interference between independent dictates precise nature imaging, for example, an anti-symmetric projection, recorded image is contrast-reversed version object—where object bright, dark, vice...

Abstract Information exchange between two distant parties, where information is shared without physically transporting it, a crucial resource in future quantum networks. Doing so with high-dimensional states offers the promise of higher capacity and improved resilience to noise, but progress date has been limited. Here we demonstrate how nonlinear parametric process allows for arbitrary state projections spatial degree freedom, strong coherent field enhances probability process. This us...

We demonstrate the generation of high-quality tunable terahertz (THz) vortices in an eigenmode by employing soft-aperture difference frequency vortex and Gaussian modes. The generated THz output exhibits a orbital angular momentum (OAM) mode with topological charge ℓTHz = ±1 range 2-6 THz. maximum average power obtained was ∼3.3 µW at 4

Orbital angular momentum (OAM) beams with topological charge ℓ are commonly generated and detected by modulating an incoming field azimuthal phase profile of the form exp(iℓϕ) a variety approaches. This results in unwanted radial modes reduced power desired OAM mode. Here, we show how to enhance modal purity creation detection classical quantum photons. Classically, combine holographic metasurface control produce high detect them efficiency, extending demonstration realm spatial light...

We report a simple single-pixel imaging system with low mean squared error in the entire terahertz frequency region (3-13 THz) that employs thin metallic ring series of directly perforated random masks and subpixel mask digitization technique. This produces high pixel resolution reconstructed images, up to 1200 x pixels, area 32 mm mm. It can be extended develop advanced systems near-ultraviolet region.

We demonstrate experimentally that spontaneous parametric down-conversion in an Al x Ga 1-x As semiconductor Bragg reflection waveguide can make for paired photons highly entangled the polarization degree of freedom at telecommunication wavelength 1550 nm.The pairs show visibility higher than 90% several bases and violate a Clauser-Horne-Shimony-Holt Bell-like inequality by more 3 standard deviations.This represents significant step toward realization efficient versatile self pumped sources...

The intricate optical distortions that occur when light interacts with complex media, such as few- or multi-mode fiber, often appear random in origin and are a fundamental source of error for communication sensing systems. We propose the use orbital angular momentum (OAM) feature extraction to mitigate phase-noise allow intermodal-coupling an effective tool fiber sensing. OAM is achieved by passive all-optical demultiplexing, we demonstrate bend tracking 94.1% accuracy. Conversely, accuracy...

Using spatial modes for quantum key distribution (QKD) has become highly topical due to their infinite dimensionality, promising high information capacity per photon. However, distortions reduce the feasible secret rates and compromise security of a channel. In an extreme form such distortion might be physical obstacle, impeding line-of-sight free-space channels. Here, by controlling radial degree freedom photon's mode, we are able demonstrate hybrid high-dimensional QKD through obstacles...

We demonstrate a scheme to generate noncoherent and coherent correlations, i.e., tunable degree of entanglement, between degrees freedom single photon. Its nature is analogous the tuning purity (first-order coherence) photon forming part two-photon state by tailoring correlations paired photons. Therefore, well-known tools such as Clauser-Horne-Shimony-Holt (CHSH) Bell-like inequality can also be used characterize entanglement freedom. More specifically, CHSH tests are performed, making use...

Traditional ghost imaging experiments exploit position correlations between correlated states of light. These occur directly in spontaneous parametric down-conversion (SPDC), and such a scenario, the two-photon state used for is symmetric. Here we perform using an anti-symmetric state, engineering symmetry by means Hong-Ou-Mandel interference. We use both symmetric show that setup configuration results object-image rotations depending on selected. Further, object arms employ spatial light...

Controlling light with subwavelength-designed metasurfaces (MSs) has allowed for the arbitrary creation of structured by precisely engineered matter. We report on purity and conversion efficiency hybrid orbital angular momentum (OAM)-generating MSs. use a recently reported method to design fabricate meta-surfaces that exploit generalized spin-orbit coupling produce vector OAM states asymmetric superpositions, e.g., 1 5, coupled linear circular polarization states, fractional values 3.5 6.5,...

We demonstrate the selection of twisted light carrying Orbital Angular Momentum (OAM) l = 100 with an 88% purity by arbitrary spin-to-orbit coupling inside a visible solid-state laser metasurface device.

The efficient creation and detection of spatial modes light has become topical late, driven by the need to increase photon bit-rates in classical quantum communications. Such mode creation/detection is traditionally achieved with tools based on linear optics. Here we put forward a new technique nonlinear optical process sum-frequency generation. We outline concept theoretically demonstrate it experimentally intense laser beams carrying orbital angular momentum Hermite-Gaussian modes....

The concept of entanglement was originally introduced to explain correlations existing between two spatially separated systems, that cannot be described using classical ideas. Interestingly, in recent years, it has been shown similar can observed when considering different degrees freedom a single system, even one. Surprisingly, also suggested might playing relevant role certain biological processes, such as the functioning pigment-proteins constitute light-harvesting complexes...

We demonstrate the formation of surface relief structures in azo-polymers which exhibit multiple spiral arms, through irradiation a rotating petal-like beam formed by coherent superposition Laguerre-Gaussian modes with opposite handedness. Intriguingly, fabricated reflect full geometric parameters irradiated petal beam, such as handedness, topological charge, initial azimuthal phase and even ellipticity, corresponding to polar angles along equator meridian planes an orbital Poincaré sphere....

We consider an interferometer based on the concept of induced coherence, where two photons that originate in different second-order nonlinear crystals can interfere. derive a complementarity relationship links first-order coherence between interfering with parameter quantifies distinguishing information regarding crystal they originated. show derived goes beyond single-photon regime and is valid for any photon-flux rate generated. report experimental results low confirm validity...

Intermodal coupling and phase noise distorts optical fields as they propagate in fiber, limiting the accuracy of sensors. Utilising structured-light illumination mode-demultiplexing for all-optical feature extraction, machine learning can be used to accurately determine shape few or multimode fibers. Full-text article not available; see video presentation