There is an improvement in the performance of low-power level signals, corresponding to 03dB and 1dB enhancements. The 3D non-orthogonal multiple access (3D-NOMA) approach exhibits the potential for a greater number of users compared to 3D orthogonal frequency-division multiplexing (3D-OFDM), without any notable performance loss. The superior performance of 3D-NOMA makes it a likely contender for future optical access systems.

A three-dimensional (3D) holographic display is impossible without the critical use of multi-plane reconstruction. A fundamental concern within the conventional multi-plane Gerchberg-Saxton (GS) algorithm is the cross-talk between planes, primarily stemming from the omission of interference from other planes during the amplitude update at each object plane. To attenuate multi-plane reconstruction crosstalk, this paper introduces the time-multiplexing stochastic gradient descent (TM-SGD) optimization approach. In order to decrease the inter-plane crosstalk, the global optimization function within stochastic gradient descent (SGD) was first implemented. While crosstalk optimization is helpful, its positive effect is weakened when the number of object planes increases, due to the discrepancy between the volume of input and output data. Using the time-multiplexing approach, we improved the iterative and reconstructive processes within the multi-plane SGD algorithm to maximize the input information. Multiple sub-holograms, produced by iterative loops in TM-SGD, are subsequently refreshed on the spatial light modulator (SLM). The optimization dynamics between holographic planes and object planes transition from a one-to-many arrangement to a many-to-many configuration, resulting in enhanced optimization of the crosstalk phenomenon between these planes. The persistence of vision allows multiple sub-holograms to jointly reconstruct crosstalk-free, multi-plane images. Experimental and simulated data demonstrated that TM-SGD successfully decreased inter-plane crosstalk and improved image quality.

A demonstrated continuous-wave (CW) coherent detection lidar (CDL) can identify micro-Doppler (propeller) signatures and capture raster-scanned images of small unmanned aerial systems/vehicles (UAS/UAVs). Utilizing a narrow linewidth 1550nm CW laser, the system benefits from the established and affordable fiber-optic components readily available in the telecommunications market. From a distance of 500 meters or less, the characteristic rhythms of drone propellers have been ascertained through lidar systems that use either collimated or focused laser beams. Moreover, by raster-scanning a concentrated CDL beam using a galvo-resonant mirror beamscanner, two-dimensional images of UAVs in flight, up to a distance of 70 meters, were successfully acquired. Lidar return signal amplitude and the target's radial speed are characteristics presented by each pixel in raster-scanned images. UAV types are distinguishable, from raster-scanned images acquired at a rate of up to five frames per second, by their shapes, as well as the payloads they may be carrying. The anti-drone lidar, when suitably enhanced, offers a compelling alternative to the expensive EO/IR and active SWIR cameras that are crucial in counter-UAV systems.

Data acquisition is essential for generating secure secret keys in a continuous-variable quantum key distribution (CV-QKD) system. The prevailing assumption in data acquisition methods is a consistent channel transmittance. Despite the stability of the channel, the transmittance in free-space CV-QKD fluctuates significantly during quantum signal propagation, making previous methods inadequate for this specific circumstance. A dual analog-to-digital converter (ADC) is leveraged in the data acquisition scheme proposed in this paper. A dynamic delay module (DDM) is integral to this high-precision data acquisition system. Two ADCs, with a sampling frequency matching the system's pulse repetition rate, eliminate transmittance fluctuations by dividing the ADC data. Through simulation and practical proof-of-principle experiments, the scheme's effectiveness in free-space channels is established, allowing for high-precision data acquisition even with fluctuating channel transmittance and a very low signal-to-noise ratio (SNR). We additionally showcase the direct application scenarios of the proposed scheme within a free-space CV-QKD system, proving their feasibility. Promoting the experimental realization and practical application of free-space CV-QKD is significantly advanced by this method.

The quality and precision of femtosecond laser microfabrication methods are being considered for enhancement through the employment of sub-100 femtosecond pulses. Yet, the application of these lasers at pulse energies frequently utilized in laser processing often leads to the distortion of the laser beam's temporal and spatial intensity distribution through nonlinear propagation effects in the air. This distortion complicates the precise mathematical forecasting of the ultimate crater shape in materials subjected to such laser ablation. This study's method, using nonlinear propagation simulations, enabled the quantitative prediction of ablation crater shapes. Investigations into the ablation crater diameters, calculated using our method, showed excellent quantitative agreement with experimental results for a variety of metals, spanning a two-orders-of-magnitude range in pulse energy. A clear quantitative correlation was observed between the simulated central fluence and the depth of ablation in our investigation. These methods aim to enhance the controllability of laser processing, particularly when using sub-100 fs pulses, and advance their practical applicability across a broad spectrum of pulse energies, encompassing cases with nonlinear pulse propagation.

Low-loss, short-range interconnects are now essential for emerging data-intensive technologies, unlike existing interconnects which suffer from high losses and a limited aggregate data throughput capacity due to insufficient interface design. Employing a tapered silicon interface, an efficient 22-Gbit/s terahertz fiber link is demonstrated, achieving coupling between the dielectric waveguide and the hollow core fiber. By examining fibers with core diameters of 0.7 mm and 1 mm, we explored the fundamental optical attributes of hollow-core fibers. Our 0.3 THz band experiment, using a 10 cm fiber, resulted in a 60% coupling efficiency and a 150 GHz 3-dB bandwidth.

Leveraging non-stationary optical field coherence theory, we define a novel class of partially coherent pulse sources incorporating the multi-cosine-Gaussian correlated Schell-model (MCGCSM), and subsequently calculate the analytical expression for the temporal mutual coherence function (TMCF) of the MCGCSM pulse beam when traversing dispersive media. Numerical studies of the temporally averaged intensity (TAI) and the temporal degree of coherence (TDOC) of MCGCSM pulse beams in dispersive media are performed. PF-04620110 in vivo The evolution of the pulse beam, from a single beam to either multiple subpulses or a flat-topped TAI distribution, during propagation is contingent on controlling the parameters of the source, as indicated by our results. PF-04620110 in vivo Additionally, a chirp coefficient falling below zero results in MCGCSM pulse beams traversing dispersive media displaying the hallmarks of two concurrent self-focusing phenomena. From a physical standpoint, the dual self-focusing processes are elucidated. The results of this paper indicate that pulse beam capabilities extend to multiple pulse shaping and applications in laser micromachining and material processing.

The appearance of Tamm plasmon polaritons (TPPs) stems from electromagnetic resonant phenomena, specifically at the interface between a metallic film and a distributed Bragg reflector. SPPs, unlike TPPs, lack the combined cavity mode properties and surface plasmon characteristics that TPPs exhibit. The propagation properties of TPPs are subjected to a rigorous investigation in this paper. Nanoantenna couplers allow polarization-controlled TPP waves to propagate in a directed fashion. Fresnel zone plates, when integrated with nanoantenna couplers, produce an asymmetric double focusing effect on TPP waves. PF-04620110 in vivo The radial unidirectional coupling of the TPP wave is facilitated by nanoantenna couplers arranged in a circular or spiral formation. This arrangement surpasses the focusing ability of a simple circular or spiral groove, resulting in a four-fold greater electric field intensity at the focal point. TPPs' excitation efficiency is greater than that of SPPs, while propagation loss is lower in TPPs. Numerical analysis indicates that TPP waves hold substantial potential for integration in photonics and on-chip devices.

To attain high frame rates and seamless streaming simultaneously, we present a compressed spatio-temporal imaging system built through the synergistic use of time-delay-integration sensors and coded exposure methods. Unlike existing imaging modalities, this electronic-domain modulation achieves a more compact and robust hardware structure without the need for supplementary optical coding elements and their calibration. Through the application of the intra-line charge transfer process, we cultivate super-resolution in both the temporal and spatial domains, consequently escalating the frame rate to reach millions of frames per second. In addition to the forward model with its post-tunable coefficients and two arising reconstruction approaches, a flexible post-interpretation of voxels is achieved. Proof-of-concept experiments and numerical simulations demonstrate the effectiveness of the proposed framework. Due to its extended observation period and adaptable voxel analysis capabilities after image acquisition, the proposed system is well-suited for imaging random, non-repeating, or long-term events.

A trench-assisted, twelve-core, five-mode fiber is proposed, featuring a low-refractive-index circle and a high-refractive-index ring (LCHR) structure. Within the 12-core fiber, a triangular lattice arrangement is observed.