HPP, integrated with the strategy for complete manipulation of CP wave amplitude and phase, facilitates intricate field manipulation, making it a promising solution for antenna applications, including anti-jamming and wireless communications.
Demonstrated here is an isotropic device, the 540-degree deflecting lens, characterized by a symmetric refractive index, that deflects parallel beams by 540 degrees. The refractive index gradient's representation is derived and presented in a generalized manner. We conclude that the device under scrutiny is an absolute optical instrument with self-imaging properties. Employing conformal mapping, we ascertain the general form within a one-dimensional space. We're introducing a combined lens, the generalized inside-out 540-degree deflecting lens, sharing structural similarities with the inside-out Eaton lens. Their characteristics are illustrated through the application of ray tracing and wave simulations. The presented study augments the family of absolute instruments, contributing novel insights into the development of optical systems.
Two competing models for the ray optical analysis of PV modules are considered, both featuring a colored interference layer system integrated into the cover glass. Employing a microfacet-based bidirectional scattering distribution function (BSDF) model and ray tracing, light scattering is characterized. Within the context of the MorphoColor application, the microfacet-based BSDF model is shown to be largely adequate for the structures used. Structures with extreme angles and very steep slopes, demonstrating correlated heights and surface normal orientations, are the only ones that display a significant influence from structure inversion. Regarding angle-independent color, a model-based assessment of potential module configurations suggests a significant advantage for a layered structure over planar interference layers alongside a scattering structure on the front surface of the glass.
High-contrast gratings (HCGs) serve as a platform for developing a theory of refractive index tuning for symmetry-protected optical bound states (SP-BICs). The derivation of a compact analytical formula for tuning sensitivity is numerically verified. In HCGs, we discovered a novel kind of SP-BIC having an accidental spectral singularity, which is attributed to the hybridization and strong coupling effects between the odd- and even-symmetric waveguide-array modes. The physics of tuning surface plasmon-induced chiral Bragg structures (SP-BICs) within high-contrast gratings (HCGs) is revealed in our study, which significantly streamlines their design and optimization for dynamic applications like light modulation, adjustable filtering, and sensor systems.
To foster progress in THz technology, encompassing applications like sixth-generation communications and THz sensing, the implementation of effective methods to control terahertz (THz) waves is imperative. In order to achieve this, the creation of tunable THz devices with large-scale intensity modulation capabilities is necessary. Two ultrasensitive devices for dynamic THz wave manipulation, driven by low-power optical excitation, are experimentally showcased here. These devices integrate perovskite, graphene, and a metallic asymmetric metasurface. The hybrid metadevice, based on perovskite materials, demonstrates ultra-sensitive modulation, achieving a maximum transmission amplitude modulation depth of 1902% under a low optical pump power of 590 mW/cm2. Furthermore, the graphene-based hybrid metadevice achieves a maximum modulation depth of 22711% at a power density of 1887 mW/cm2. Optical modulation of THz waves with ultrasensitive devices is advanced by this work's contribution.
We present optics-integrated neural networks in this paper, showcasing their experimental improvements to end-to-end deep learning models for optical IM/DD transmission links. Models utilizing optics, either as an inspiration or as a guiding principle, are characterized by the use of linear and/or nonlinear components whose mathematical structure is directly based on the reactions of photonic devices. Their construction is rooted in the ongoing advancements of neuromorphic photonics, and their training processes are carefully adapted to reflect this. For end-to-end deep learning in fiber optic communication networks, we analyze the application of a novel activation function, the Photonic Sigmoid, a variant of the logistic sigmoid function, derived from a semiconductor-based nonlinear optical module. End-to-end deep learning fiber optic link demonstrations utilizing state-of-the-art ReLU-based configurations are surpassed by optics-informed models employing the photonic sigmoid function, exhibiting improved noise and chromatic dispersion compensation in fiber optic intensity modulation/direct detection links. Rigorous simulations and experimentation uncovered significant performance gains for Photonic Sigmoid NNs, resulting in the reliable transmission of data at 48 Gb/s over fiber optic links up to 42 km, staying within the Hard-Decision Forward Error Correction limitations.
Unprecedented information on cloud particle density, size, and position is accessible through holographic cloud probes. Within a large volume, each laser shot captures particles, which images can then be computationally refocused to reveal particle size and location details. Despite this, the processing of these holographic images using conventional methods or machine learning algorithms requires substantial computational resources, time commitments, and sometimes, direct human input. The training of ML models relies on simulated holograms produced by the physical probe model, as real holograms do not possess absolute truth values. Lab Equipment The application of an alternative method to produce labels will introduce inaccuracies that will be passed on to the machine learning model. The performance of models on real holograms is enhanced when the training process involves image corruption in the simulated images, precisely mimicking the unpredictable nature of the actual probe. A tedious manual labeling process is required for effective image corruption optimization. We present here the application of the neural style translation method to simulated holograms. A pre-trained convolutional neural network transforms the simulated holograms, rendering them evocative of the authentic holograms observed using the probe, all the while retaining the simulated image's inherent characteristics, such as the position and scale of the particles. Upon training an ML model on stylized particle datasets for predicting locations and shapes, we observed comparable performance on both simulated and real holograms, eliminating the requirement of manual labeling. The method outlined for holograms isn't unique to them and can be translated to other contexts for better mimicking real-world observations in simulations, by accounting for the noise and flaws of observation instruments.
We simulate and experimentally demonstrate a micro-ring resonator, an IG-DSMRR, based on a silicon-on-insulator platform, possessing a central slot ring with a radius of 672 meters. In glucose solutions, this novel photonic-integrated optical sensor for label-free biochemical analysis exhibits an enhanced refractive index (RI) sensitivity of 563 nm/RIU, while the limit of detection is 3.71 x 10⁻⁶ RIU (refractive index units). Sodium chloride solution concentration sensitivity can attain 981 picometers per percentage point, while the lowest detectable concentration stands at 0.02 percent. Leveraging the combined effect of DSMRR and IG, the detectable range is significantly extended to 7262 nm, a three-fold increase compared to the typical free spectral range of conventional slot micro-ring resonators. A Q-factor of 16104 was determined; correspondingly, the straight strip waveguide exhibited a transmission loss of 0.9 dB/cm, and the double slot waveguide a loss of 202 dB/cm. The IG-DSMRR, through the innovative amalgamation of micro ring resonators, slot waveguides, and angular gratings, is extremely beneficial for biochemical sensing in liquid and gaseous media, exhibiting ultra-high sensitivity and an ultra-wide measurable range. Ipatasertib This is the initial report on a fabricated and measured double-slot micro ring resonator, highlighting its significant inner sidewall grating structure.
The fundamental principles of scanning-based image generation differ substantially from those underlying classical lens-based methods. Thus, existing classical performance assessment techniques are unable to establish the theoretical limitations of optical systems employing scanning procedures. We created a simulation framework and a new performance evaluation process for measuring the achievable contrast of scanning systems. Our study, which employed these tools, examined the resolution limits associated with distinct Lissajous scanning strategies. An innovative approach, for the first time, details and quantifies the spatial and directional connections of optical contrast, highlighting their significant influence on the perceived image quality. Transiliac bone biopsy Systems composed of Lissajous figures with elevated ratios of scanning frequencies exhibit more noticeable effects. The presented approach and outcomes can serve as a springboard for a more complex, application-driven design of next-generation scanning systems.
An end-to-end (E2E) fiber-wireless integrated system benefits from the intelligent nonlinear compensation method we propose and experimentally validate, integrating a stacked autoencoder (SAE) model, principal component analysis (PCA), and a bidirectional long-short-term memory coupled with artificial neural network (BiLSTM-ANN) nonlinear equalizer. The SAE-optimized nonlinear constellation is used to address nonlinearity during the optical and electrical conversion stages. Information and time-based memory are central to our BiLSTM-ANN equalizer's design, enabling it to overcome and manage remaining nonlinear redundancies. Transmission of a 50 Gbps, low-complexity, nonlinear 32 QAM signal optimized for end-to-end transmission was achieved over a 20 km standard single-mode fiber (SSMF) span combined with a 6 m wireless link at 925 GHz. Empirical results obtained from an extended experimental study support the claim that the proposed end-to-end system is capable of reducing bit error rate by as much as 78% and improving receiver sensitivity by over 0.7dB, at a bit error rate of 3.81 x 10^-3.