The image represents the interactions of a ?at spiral shaped particle with an incident beam of light. From the perspective of spatial symmetries, this spiral is not a geometrical chiral object. However, thanks to the framework developed in the article, it can be demonstrated that the particle nonetheless exhibits pseudochiral responses in the form of quadrupolar contributions.
The image shows fast object detection and data analysis of high-power high-repetition-rate laserplasma experiment using neural networks. In the petawatt, Hz laser system at the Center for Advanced Laser Applications, Munich, object detection networks are used to rapidly process and visualize various diagnostic data from each frame of the laser’s output images, including electron energy spectra, plasma wave, and laser damage.
Helical laser beams, due to their unique ?eld structure, are ideal optical drivers for producing monoenergetic, pellet-like electron bunches. In contrast to regular laser beams, their ?eld structure close to the axis of the beam is dominated by longitudinal electric and magnetic ?elds. The bunches are generated as a result of two synergetic e?ects that take place when such a beam is re?ected o? a mirror: the longitudinal electric ?eld accelerates electrons after extracting them from the mirror surface; while the magnetic ?eld con?nes them into the central region, allowing for acceleration within the laser over a long duration.
The cover image illustrates the photonic quasicrystal fiber (PQF), which is also named quasiperiodic photonic crystal fiber. The five insets surrounding the PQF end-face provide a simultaneous display of three typical structures and two representative potential applications of PQF. The three white-circled insets (top-left, right, and bottom-left) represent the Stampfli-type, Penrose-type, and Sunflower-type structures, respectively. The two blue-circled insets (left and bottom-right) show applications of the supercontinuum generation and orbital angular momentum mode propagation, respectively.
By harnessing Tamm plasmon coupling, spintronics THz radiation not only achieved a 264% enhancement but guaranteed nearly lossless (~4%) THz transmission. This approach provides the compatible optical structure design and the low energy consumption for ultrafast opto-spintronics devices.
The manipulation and detection of polarization states play a crucial role in the application of 6G terahertz communication. Nonetheless, the development o
The manipulation and detection of polarization states play a crucial role in the application of 6G terahertz communication. Nonetheless, the development of compact and versatile polarization detection devices capable of detecting arbitrary polarizations continues to be a challenging endeavor. Here, we demonstrate a terahertz polarization detection scheme by performing mode purity analysis and multidimensional analysis of the transmitted vortex field. The power of the proposed polarization recognition is verified by using three polarization trajectories, including linear polarizations, circular polarizations, and elliptical polarizations. Using the reconstructed complete polarization parameters, the detected polarization states are characterized using polarization ellipses, Poincaré sphere, and full-Stokes parameters. The experimental results validate the power of this scheme in polarization detection. This scheme holds promise for applications in polarization imaging and terahertz communication.show less
Polarimetric imaging provides valuable insights into the polarization state of light interacting with a sample. It can infer crucial birefringence propert
Polarimetric imaging provides valuable insights into the polarization state of light interacting with a sample. It can infer crucial birefringence properties of specimens without using labels, thereby facilitating the diagnosis of diseases such as cancer and osteoarthritis. In this study, we present a novel polarimetric coded ptychography (pol-CP) approach that enables high-resolution, high-throughput gigapixel birefringence imaging on a chip. Our platform deviates from traditional lens-based systems by employing an integrated polarimetric coded sensor for lensless coherent diffraction imaging. Utilizing Jones calculus, we quantitatively determine the birefringence retardance and orientation information of biospecimens from the recovered images. Our portable pol-CP prototype can resolve the 435 nm linewidth on the resolution target, and the imaging field of view for a single acquisition is limited only by the detector size of
The fabrication of different perovskite materials with superior properties into lateral heterostructures can greatly improve device performance and polari
The fabrication of different perovskite materials with superior properties into lateral heterostructures can greatly improve device performance and polarization sensitivity. However, the sensitivity of perovskites to solvents and environmental factors makes the fabrication of lateral heterojunctions difficult. Here, we realize high-quality perovskite microwire crystal heterojunction arrays using regioselective ion exchange. Photodetectors with responsivity and detectivity up to
High-precision time interval measurement is a fundamental technique in many advanced applications, including time and distance metrology, particle physics
High-precision time interval measurement is a fundamental technique in many advanced applications, including time and distance metrology, particle physics, and ultra-precision machining. However, many of these applications are confined by the imprecise time interval measurement of electrical signals, restricting the performance of the ultimate system to a few picoseconds, which limits ultrahigh precision applications. Here, we demonstrate an optical means for the time interval measurement of electrical signals that can successfully achieve femtosecond (fs) level precision. The setup is established using the optical frequency comb (OFC) based linear optical sampling (LOS) technique to realize timescale-stretched measurement. We achieve a measurement precision of 82 fs for a single LOS scan measurement and 3.05 fs for the 100-times average with post-processing, which is three orders of magnitude higher than the results of older electrical methods. The high-precision time interval measurement of electrical signals can substantially improve precision measurement technologies.show less
The array spatial light field is an effective means to improve imaging speed in single-pixel imaging. However, distinguishing the intensity values of each sub-light field in the array spatial li
The array spatial light field is an effective means to improve imaging speed in single-pixel imaging. However, distinguishing the intensity values of each sub-light field in the array spatial light field requires the help of the array detector or time-consuming deep-learning algorithm. Aiming at this problem, we propose measurable speckle gradation Hadamard single-pixel imaging (MSG-HSI) which makes the most of the refresh mechanism of the device generating Hadamard speckle patterns and high sampling rate of the bucket detector, and is capable of measuring the light intensity fluctuation of the array spatial light field only by a simple bucket detector. The numerical and experimental results indicate that data acquisition in MSG-HSI is 4 times faster than traditional Hadamard single-pixel imaging. Moreover, imaging quality in MSG-HSI can be further improved by image stitching technology. Our approach may open a new perspective for single-pixel imaging to improve imaging speed.show less
The 3D location and dipole orientation of light emitters provide essential information in many biological, chemical and physical systems. Simultaneous acquisition of both information typically r
The 3D location and dipole orientation of light emitters provide essential information in many biological, chemical and physical systems. Simultaneous acquisition of both information typically requires pupil engineering for 3D localization and dual-channel polarization splitting for orientation deduction. Here we report a geometric-phase helical point-spread function for simultaneously estimating the 3D position and dipole orientation of point emitters. It has a compact and simpler optical configuration compared to polarization splitting techniques and yields achromatic phase modulation in contrast to dynamic-phase-based pupil engineering, showing great potential for single-molecule orientation and localization microscopy.show less
Data exchange between different mode channels is essential in the optical communication network with mode division multiplexing (MDM). However, there are challenges in realizing mode exchange wi
Data exchange between different mode channels is essential in the optical communication network with mode division multiplexing (MDM). However, there are challenges in realizing mode exchange with low insert loss, low mode crosstalk, and high integration. Here, we designed and fabricated a mode exchange device based on multiplane light conversion (MPLC), which supports the transmission of LP01, LP11a, LP11b, and LP21 modes in C-band and L-band. The simulated exchanged mode purities are greater than 85%. The phase masks are fabricated on a silicon substrate to facilitate the integration with optical systems, with an insert loss of less than 2.2 dB and mode crosstalk below -21dB due to machining inaccuracies and alignment errors primarily. We carried out an optical communication experiment with 10Gbit/s OOK and QPSK data transmission at the wavelength of 1550 nm and obtained excellent performance with the device. It paves the way for flexible data exchange as a building block in MDM optical communication networks.show less
We propose and demonstrate an integrated microwave photonic sideband selector based on thin-film lithium niobate (TFLN) platform by integrating an electro-optic Mach-Zehnder modulator (MZM) and
We propose and demonstrate an integrated microwave photonic sideband selector based on thin-film lithium niobate (TFLN) platform by integrating an electro-optic Mach-Zehnder modulator (MZM) and a thermo-optic tunable flat-top microring filter. The sideband selector has two functions: electro-optic modulation of wideband RF signal and sideband selection. The microwave photonic sideband selector supports processing RF signals up to 40 GHz, with undesired sidebands effectively suppressed by more than 25 dB. The demonstrated device shows great potential of TFLN integrated technology in microwave photonic applications, such as mixing and frequency measurement.show less