Apprehending the influence of metallic patches on near-field focusing in patchy particles is vital for the deliberate design of a nanostructured microlens. Employing both theoretical and experimental methods, we have shown the possibility of focusing and manipulating light waves using patchy particles in this research. Coating dielectric particles in silver film can produce light beams having either a hook-like or an S-shaped form. Based on simulation findings, the waveguide properties of metal films and the geometric asymmetry of patchy particles are the cause of S-shaped light beam formation. The far-field characteristics of S-shaped photonic hooks, in comparison to classical photonic hooks, demonstrate an enhanced effective length and a diminished beam waist. Multi-functional biomaterials Investigations were undertaken to showcase the creation of classical and S-shaped photonic hooks from inhomogeneous microspheres.
Previously published research included a fresh design for liquid-crystal polarization modulators (LCMs) that do not drift, featuring liquid-crystal variable retarders (LCVRs). This research investigates the performance of their polarimeter systems, encompassing both Stokes and Mueller polarimeters. LCMs, demonstrating polarimetric responses akin to LCVRs, present a temperature-stable alternative to the widespread use of LCVR-based polarimeters. We constructed a polarization state analyzer (PSA) using LCM methods, and then benchmarked its performance against an equivalent LCVR-based PSA design. Despite significant temperature fluctuations ranging from 25°C to 50°C, our system parameters remained unchanged. Accurate measurements of Stokes and Mueller parameters led to the development of polarimeters that do not require calibration, thereby enabling their application in demanding scenarios.
Augmented and virtual reality (AR/VR), in recent years, has witnessed significant attention and funding from both the technology and academic spheres, spurring a fresh wave of creative developments. Capitalizing on this dynamic progress, this feature was launched to encompass the latest innovations within the expanding field of optics and photonics. To complement the 31 published research articles, this introduction provides readers with insights into the stories behind the research, submission data, reading recommendations, author profiles, and editor viewpoints.
Employing an asymmetric Mach-Zehnder interferometer on a monolithic silicon-photonics platform within a commercial 300-mm CMOS foundry, we experimentally demonstrate wavelength-independent couplers. The study compares splitter performance utilizing MZIs with circular and third-order Bezier curves. To precisely determine the response of each device, a semi-analytical model is formulated, taking into account its unique geometrical characteristics. Both 3D-FDTD simulation results and experimental characterization data indicate successful model testing. Various target splitting ratios resulted in uniform performance across the different wafer sites, as demonstrated by the experimental results. The Bezier bend design consistently outperforms the circular bend design in both insertion loss (0.14 dB) and the reliability of its performance across different wafer samples. check details Over a span of 100 nanometers in wavelength, the optimal device's splitting ratio's maximum deviation is 0.6%. The devices, moreover, have a compact footprint of 36338 square meters.
The spectral and beam quality evolution in high-power near-single-mode continuous-wave fiber lasers (NSM-CWHPFLs) was simulated using a time-frequency evolution model driven by intermodal nonlinearity, encompassing the combined effects of both intermodal and intramodal nonlinearity. Investigating the impact of fiber laser parameters on intermodal nonlinearities, a method for their suppression using fiber coiling and optimized seed mode characteristics was formulated. The verification process involved the use of 20/400, 25/400, and 30/600 fiber-based NSM-CWHPFLs. The accuracy of the theoretical model is showcased by the results, which also elucidate the physical mechanisms behind nonlinear spectral sidebands, and demonstrate the comprehensive optimization of intermodal-nonlinearity-induced spectral distortion and mode degradation.
Analytical derivation of the propagation of an Airyprime beam, exhibiting first and second-order chirped factors, is presented, providing an expression for its free-space trajectory. A greater peak light intensity on a viewing plane not the original plane, compared to the intensity on the original plane, is designated as interference enhancement; this is a result of the coherent superposition of chirped Airy-prime and chirped Airy-related modes. A theoretical study, on a per-factor basis, analyzes the effects of first-order and second-order chirped factors on the boosting of interference effects. The maximum light intensity within the transverse coordinates is entirely determined by the first-order chirped factor's effect. The interference enhancement effect of a chirped Airyprime beam, characterized by a negative second-order chirped factor, surpasses that of an ordinary Airyprime beam. Although the interference enhancement effect's strength is improved by the negative second-order chirped factor, this improvement is unfortunately linked to a decrease in the position of the maximum light intensity and the scope of the interference enhancement effect. The experimentally generated Airyprime beam, characterized by its chirped nature, also exhibits demonstrably enhanced interference effects, as evidenced by the experimental confirmation of the impact of both first-order and second-order chirped factors. This study details a method for increasing the strength of the interference enhancement effect, achieved through control of the second-order chirped factor. In contrast to conventional methods of increasing intensity, like lens focusing, our approach is both adaptable and straightforward to execute. Spatial optical communication and laser processing find practical applications facilitated by this research.
This paper details the design and analysis of an all-dielectric metasurface. This metasurface, periodically arranged on a silicon dioxide substrate, comprises a unit cell featuring a nanocube array. The use of asymmetric parameters, acting to excite quasi-bound states in the continuum, can produce three Fano resonances with enhanced quality factors and substantial modulation depth within the near infrared spectral range. Magnetic and toroidal dipoles, acting independently yet in concert with electromagnetism's distributive qualities, are responsible for the excitation of three Fano resonance peaks. From the simulation results, it can be inferred that the outlined structure is suitable for use as a refractive index sensor, exhibiting a sensitivity of about 434 nm per RIU, a maximum Q-factor of 3327, and a 100% modulation depth. Following the experimental testing and design phase, the maximum sensitivity of the proposed structure is measured at 227 nanometers per refractive index unit. The resonance peak at 118581 nanometers demonstrates a near-complete modulation depth (approximately 100%) when the polarization angle of the incident light is zero. Consequently, the proposed metasurface finds application in optical switching systems, nonlinear optical studies, and biological sensing.
A light source's photon number variance, quantified by the time-dependent Mandel Q parameter, Q(T), is contingent upon the integration time. A quantum emitter's single-photon emission within hexagonal boron nitride (hBN) is quantitatively assessed using the Q(T) parameter. Photon antibunching was indicated by the measured negative Q parameter under pulsed excitation, measured at a 100-nanosecond integration time. In cases of increased integration duration, Q registers a positive value, manifesting as super-Poissonian photon statistics; this finding, substantiated by a three-level emitter Monte Carlo simulation, is in agreement with the effect of a metastable shelving state. With a focus on the technological implementation of hBN single-photon sources, we posit that the Q(T) characteristic provides useful information about the constancy of single-photon emission intensity. The complete characterization of a hBN emitter leverages this approach, enhancing the commonly used g(2)() function.
This work details the empirical measurement of the dark count rate in a large-format MKID array, akin to those used currently at observatories such as Subaru on Maunakea. The utility of this work is convincingly demonstrated by the evidence it presents, which is particularly relevant for future experiments needing low-count rates and quiet environments, for example, in dark matter direct detection. The 0946-1534 eV (1310-808 nm) bandpass demonstrates an average count rate of (18470003)x10^-3 photons per pixel per second. When the bandpass is divided into five equal-energy bins, considering the detector's resolving power, the average dark count rate in an MKID is found to be (626004)x10⁻⁴ photons/pixel/second within the 0946-1063 eV range and (273002)x10⁻⁴ photons/pixel/second in the 1416-1534 eV range. hand infections By reading out a single MKID pixel with lower-noise electronics, we show that the recorded events in the absence of external illumination are a combination of real photons, possibly including cosmic ray-induced fluorescence, and phonon occurrences within the array's substrate. Measurements on a single MKID pixel, using lower noise readout electronics, yielded a dark count rate of (9309)×10⁻⁴ photons/pixel/s within the bandpass of 0946-1534 eV. Furthermore, analysis of unilluminated detector responses showed signals distinctive from those of known light sources, such as lasers, which are likely attributable to cosmic-ray excitations within the MKID.
In the design of an optical system for the automotive heads-up display (HUD), a typical augmented reality (AR) application, the freeform imaging system plays a crucial role. Automated algorithms are urgently needed for the design of automotive HUDs to effectively manage the challenges of multi-configuration, including the variable height of drivers, the movement of eyeballs, correcting distortions from windshields, and considering diverse vehicle structures; however, current research is far from addressing these issues.