The validation enables the investigation of potential applications of tilted x-ray lenses in the sphere of optical design. We ascertain that while tilting 2D lenses does not seem beneficial for aberration-free focusing, tilting 1D lenses about their focal direction allows for a smooth and continuous adjustment of their focal length. Experimental evidence demonstrates a continuous shift in the apparent lens radius of curvature, R, with a reduction exceeding a factor of two, and potential applications in beamline optics are explored.
The microphysical properties of aerosols, including volume concentration (VC) and effective radius (ER), are critically important for assessing their radiative forcing and influence on climate change. Nevertheless, the spatial resolution of aerosol vertical profiles, VC and ER, remains elusive through remote sensing, barring the integrated columnar measurements achievable with sun-photometers. Employing a novel combination of partial least squares regression (PLSR) and deep neural networks (DNN), this study presents a new retrieval approach for range-resolved aerosol vertical column (VC) and extinction (ER) values, incorporating polarization lidar and AERONET (AErosol RObotic NETwork) sun-photometer data collected simultaneously. Polarization lidar measurements, commonly employed, demonstrate a suitable capability for deriving aerosol VC and ER values, as evidenced by a determination coefficient (R²) of 0.89 (0.77) for VC (ER) when employing the DNN methodology. The lidar's height-resolved vertical velocity (VC) and extinction ratio (ER) measurements at the near-surface demonstrate a strong correlation with the readings from the collocated Aerodynamic Particle Sizer (APS). Our research at the Lanzhou University Semi-Arid Climate and Environment Observatory (SACOL) indicated considerable variations in aerosol VC and ER levels across both day and season. This study, differentiating from columnar sun-photometer data, offers a practical and trustworthy approach for deriving the full-day range-resolved aerosol volume concentration and extinction ratio from widespread polarization lidar measurements, even when clouds obscure the view. In addition, the findings of this research are applicable to ongoing long-term monitoring efforts through existing ground-based lidar networks and the space-borne CALIPSO lidar, to provide a more accurate assessment of aerosol climate effects.
Single-photon imaging, with its capability of picosecond resolution and single-photon sensitivity, offers an ideal solution for ultra-long distance imaging in extreme environments. see more Current single-photon imaging technology's shortcomings include slow imaging speeds and poor quality images, which are directly attributable to quantum shot noise and fluctuations in background noise. This work details the development of a high-performance single-photon compressed sensing imaging scheme, where a novel mask is formulated using both Principal Component Analysis and Bit-plane Decomposition algorithms. Optimizing the number of masks, considering the effects of quantum shot noise and dark counts on imaging, leads to high-quality single-photon compressed sensing imaging at different average photon counts. The imaging speed and quality have experienced a considerable upgrade relative to the habitually employed Hadamard method. A 6464-pixel image was acquired with a mere 50 masks in the experiment, indicating a 122% sampling compression rate and an 81-times acceleration of sampling speed. Experimental and simulated results unequivocally support the assertion that the proposed approach will effectively advance the use of single-photon imaging in practical applications.
High-precision X-ray mirror surface profiling was accomplished through a differential deposition technique, rather than a method involving direct material removal. For modifying the form of a mirror surface through the differential deposition approach, a thick film coating is essential, and co-deposition technique is used to prevent the magnification of surface irregularities. Carbon's incorporation within the platinum thin film, typically used as an X-ray optical thin film, diminished surface roughness relative to a platinum-only coating, and the corresponding stress variation as a function of thin film thickness was evaluated. The substrate's velocity during coating is regulated by differential deposition, a process governed by continuous motion. By employing deconvolution calculations on accurately measured unit coating distribution and target shape data, the dwell time was determined, thereby controlling the stage. We achieved success in fabricating an X-ray mirror with exceptionally high precision. Manufacturing an X-ray mirror surface, according to this study, is achievable through a coating process which modifies the surface shape on a micrometer scale. Modifying the contours of current mirrors can produce highly precise X-ray mirrors, and at the same time, elevate their operational standards.
Employing a hybrid tunnel junction (HTJ), we showcase the vertical integration of nitride-based blue/green micro-light-emitting diode (LED) stacks, with individually controllable junctions. Using metal organic chemical vapor deposition (p+GaN) and molecular-beam epitaxy (n+GaN), the hybrid TJ was grown. Different types of junction diodes are capable of producing a uniform blue, green, or blue/green emission. The external quantum efficiency (EQE) of TJ blue LEDs, with indium tin oxide contacts, reaches a peak of 30%, while the corresponding value for green LEDs is 12%. A discourse on the transportation of charge carriers across disparate junction diodes was presented. The research presented here points towards a promising approach for the integration of vertical LEDs, which aims to enhance the output power of individual LED chips and monolithic LEDs exhibiting varied emission colors by permitting independent control of their junctions.
Applications of infrared up-conversion single-photon imaging encompass remote sensing, biological imaging, and night vision. The employed photon-counting technology unfortunately exhibits a significant limitation in the form of an extended integration time and sensitivity to background photons, which restricts its practical utility in real-world applications. This paper proposes a novel single-photon imaging method employing passive up-conversion, specifically utilizing quantum compressed sensing to acquire the high-frequency scintillation information from a near-infrared target. Infrared target imaging, through frequency domain analysis, substantially enhances the signal-to-noise ratio despite significant background noise. The experiment tracked a target exhibiting a flicker frequency in the gigahertz range, ultimately determining an imaging signal-to-background ratio of 1100. The practical application of near-infrared up-conversion single-photon imaging will be significantly propelled by our proposal, which greatly strengthened its robustness.
Employing the nonlinear Fourier transform (NFT), the phase evolution of solitons and first-order sidebands within a fiber laser is examined. A transition from dip-type sidebands to peak-type (Kelly) sidebands is demonstrated. According to the NFT's calculations, a good agreement exists between the phase relationship of the soliton and sidebands, and the predictions of the average soliton theory. Our research suggests that NFTs can function as a valuable instrument for the meticulous analysis of laser pulses.
Employing a cesium ultracold atomic cloud, we examine the Rydberg electromagnetically induced transparency (EIT) phenomenon in a three-level cascade atom, featuring an 80D5/2 state, in a strong interaction setting. Our experimental procedure included a strong coupling laser that caused coupling between the 6P3/2 and 80D5/2 states; a weak probe laser, stimulating the 6S1/2 to 6P3/2 transition, was used to detect the induced EIT signal. see more Metastability, induced by interaction, is evidenced by the gradual temporal decrease in EIT transmission at the two-photon resonance. see more The optical depth ODt is equivalent to the dephasing rate OD. Prior to saturation, the optical depth exhibits a linear temporal dependence for a given incident probe photon number (Rin). A non-linear connection is observed between the dephasing rate and Rin. The dominant mechanism for dephasing is rooted in robust dipole-dipole interactions, thereby initiating state transitions from the nD5/2 state to other Rydberg energy levels. The typical transfer time, of the order O(80D), obtained via state-selective field ionization, is shown to be comparable to the EIT transmission's decay time, which is of the order O(EIT). The experiment under examination furnishes a helpful instrument for the investigation of strong nonlinear optical effects and metastable states in Rydberg many-body systems.
In measurement-based quantum computing (MBQC), a substantial continuous variable (CV) cluster state is fundamental for effective quantum information processing. Experimental implementations of large-scale CV cluster states, time-division multiplexed, are easier to execute and exhibit robust scalability. Parallel generation of one-dimensional (1D) large-scale dual-rail CV cluster states, time-frequency multiplexed, is performed. Further expansion to a three-dimensional (3D) CV cluster state is enabled by utilizing two time-delayed, non-degenerate optical parametric amplification systems combined with beam-splitters. Experimental results corroborate a correlation between the number of parallel arrays and the related frequency comb lines, where the potential for each array is to include a large quantity of elements (millions), and the dimensions of the 3D cluster state may be quite substantial. Demonstrations of concrete quantum computing schemes are also provided, incorporating the generated 1D and 3D cluster states. Our schemes, which encompass efficient coding and quantum error correction, could pave the way for fault-tolerant and topologically protected MBQC in hybrid computational domains.
The ground states of a dipolar Bose-Einstein condensate (BEC) subject to Raman laser-induced spin-orbit coupling are investigated using the mean-field approximation. The interplay of spin-orbit coupling and atom-atom forces within the Bose-Einstein condensate (BEC) generates remarkable self-organizational behavior, resulting in exotic phases such as vortices with discrete rotational symmetry, spin-helix stripes, and chiral lattices with C4 symmetry.