A self-calibrated phase retrieval (SCPR) method is presented for joint recovery of both the binary mask and the sample's wave field, specifically within a lensless masked imaging system. Our approach, unlike conventional methods, yields high-performance, adaptable image recovery, entirely free from the need for additional calibration equipment. A comparative study of experimental results from different samples confirms our method's superior performance.

The proposed metagratings, designed with zero load impedance, are intended to facilitate efficient beam splitting. Unlike previous metagrating proposals, requiring specific capacitive and/or inductive structures to match load impedance, the metagrating introduced here is comprised only of simple microstrip-line components. The architecture surmounts the obstacles in implementation, thereby allowing for the application of low-cost manufacturing processes for metagratings operating at higher frequencies. The detailed theoretical design procedure, coupled with numerical optimization techniques, is showcased to obtain the specific design parameters. Subsequently, several beam-splitting apparatuses, characterized by distinct pointing angles, underwent design, simulation, and rigorous experimental evaluation. The 30GHz results showcase outstanding performance, facilitating the development of cost-effective printed circuit board (PCB) metagratings for millimeter-wave and higher frequencies.

High-quality factors are achievable with out-of-plane lattice plasmons due to the notable interparticle coupling strength. Despite this, the rigorous conditions of oblique incidence impede experimental observation. This letter proposes, as far as our knowledge extends, a novel mechanism for generating OLPs using near-field coupling. Importantly, the deployment of specially designed nanostructural dislocations enables the attainment of the strongest OLP at normal incidence. The wave vectors of Rayleigh anomalies are a key factor in determining the energy flux orientation of the OLPs. Our investigation further uncovered symmetry-protected bound states in the continuum within the OLP, thereby explaining the prior observation that symmetric structures failed to excite OLPs at normal incidence. Our exploration of OLP broadens our understanding and offers advantages in designing flexible functional plasmonic devices.

We introduce a novel, validated approach to achieve high coupling efficiency (CE) in lithium niobate on insulator grating couplers (GCs) within photonic integration platforms. Fortifying the grating on the GC with a high refractive index polysilicon layer is the method used to achieve enhanced CE. The lithium niobate waveguide's light is pulled upward to the grating region as a consequence of the polysilicon layer's high refractive index. Infectious keratitis The optical cavity, formed vertically, leads to a higher CE in the waveguide GC. The simulations, based on this novel structure, predicted a CE of -140dB. Experimental results, however, indicated a CE of -220dB, and a 3-dB bandwidth of 81nm, ranging from 1592nm to 1673nm. The high CE GC is obtained by avoiding the use of bottom metal reflectors and not requiring the etching of lithium niobate.

Ho3+-doped, single-cladding, in-house-fabricated ZrF4-BaF2-YF3-AlF3 (ZBYA) glass fibers yielded a powerfully operational 12-meter laser. check details Fibers were manufactured utilizing ZBYA glass, whose components include ZrF4, BaF2, YF3, and AlF3. Pumping a 05-mol% Ho3+-doped ZBYA fiber with an 1150-nm Raman fiber laser resulted in a maximum combined laser output power of 67 W from both sides, along with a 405% slope efficiency. We noted lasing activity at a wavelength of 29 meters, producing 350 milliwatts of power, a phenomenon linked to the Ho³⁺ ⁵I₆ to ⁵I₇ energy level transition. The influence of rare earth (RE) doping concentration and gain fiber length on laser performance was studied at 12 and 29-meter distances, respectively.

Mode-group-division multiplexing (MGDM) combined with intensity modulation direct detection (IM/DD) transmission offers a compelling strategy for increasing the capacity of short-reach optical communication. Within this letter, a straightforward but powerful mode group (MG) filtering system for MGDM IM/DD transmission is presented. The scheme's suitability encompasses all fiber mode bases, guaranteeing low complexity, low power consumption, and high system performance metrics. The proposed MG filter scheme experimentally validated a 152-Gb/s raw bit rate for a 5-km few-mode fiber (FMF) multiple-input-multiple-output (MIMO)-free in-phase/quadrature (IM/DD) system that simultaneously transmitted and received over two orbital angular momentum (OAM) channels, each carrying 38-GBaud four-level pulse amplitude modulation (PAM-4) signals. The hard-decision forward error correction (HD-FEC) BER threshold at 3810-3 is exceeded by neither MG's bit error ratios (BERs), a result of simple feedforward equalization (FFE). Consequently, the resilience and dependability of these MGDM links are of great value. Subsequently, the dynamic testing of BER and signal-to-noise ratio (SNR) is performed for each MG during a 210-minute duration, under differing situations. Applying our proposed scheme to dynamic cases, the BER outcomes are uniformly found to be less than 110-3, providing further evidence for the stability and feasibility of our multi-group decision-making (MGDM) transmission method.

Nonlinear processes in solid-core photonic crystal fibers (PCFs) provide a means for generating broadband supercontinuum (SC) light sources, leading to breakthroughs in the fields of spectroscopy, metrology, and microscopy. The persistent problem of extending the short-wavelength emission from SC sources has been the focus of intensive research for the past two decades. Nevertheless, the precise method by which blue and ultraviolet light are produced, particularly concerning certain resonant spectral peaks within the short-wavelength spectrum, remains an enigma. We show how inter-modal dispersive-wave radiation, a consequence of phase matching between pump pulses in the fundamental optical mode and packets of linear waves in higher-order modes (HOMs) within the PCF core, might be a key mechanism for producing resonance spectral components with wavelengths shorter than the pump light. The experiment demonstrated the presence of numerous spectral peaks in the blue and ultraviolet portions of the SC spectrum. The central wavelengths of these peaks are controllable through adjustments of the PCF core diameter. neuroblastoma biology The inter-modal phase-matching theory furnishes a compelling interpretation of these experimental results, offering valuable insights into the process of SC generation.

This communication details a novel, single-exposure quantitative phase microscopy technique. This technique employs phase retrieval, acquiring both the band-limited image and its Fourier transform concurrently. The intrinsic physical constraints of microscopy systems are utilized within the phase retrieval algorithm to remove the inherent ambiguities in the reconstruction and achieve rapid iterative convergence. Importantly, this system avoids the demanding object support and oversampling procedures inherent in coherent diffraction imaging. Our algorithm, as evidenced by both simulation and experiment, allows for the rapid determination of the phase from a single-exposure measurement. The presented phase microscopy is a promising tool for quantitatively visualizing biological processes in real time.

Ghost imaging, employing the temporal correlations of two optical light beams, is used to generate a temporal picture of a fleeting object. Resolution, fundamentally dependent on the speed of the photodetector, has in a recent experiment reached a significant 55 picoseconds. A spatial ghost image of a temporal object, based on the potent temporal-spatial correlations of two optical beams, is proposed for the purpose of further improving temporal resolution. Two entangled beams, sourced from type-I parametric downconversion, are known to exhibit correlations. It has been observed that a realistic entangled photon source permits access to temporal resolution at the sub-picosecond level.

Measurements of nonlinear refractive indices (n2) at 1030 nm were performed on a variety of bulk crystals (LiB3O5, KTiOAsO4, MgOLiNbO3, LiGaS2, ZnSe) and liquid crystals (E7, MLC2132) using nonlinear chirped interferometry, achieving sub-picosecond (200 fs) resolution. Design parameters for near- to mid-infrared parametric sources and all-optical delay lines are established using the reported values.

In innovative bio-integrated optoelectronic and high-end wearable systems, the inclusion of mechanically flexible photonic devices is paramount. These systems rely on thermo-optic switches (TOSs) for precise optical signal control. In this work, a Mach-Zehnder interferometer (MZI) based flexible titanium dioxide (TiO2) transmission optical switches (TOSs) were successfully implemented around 1310nm, thought to be a first-time demonstration. Per multi-mode interferometer (MMI) of flexible passive TiO2 22, the insertion loss measures -31dB. The flexible TOS boasts a power consumption (P) of 083mW, significantly better than its inflexible counterpart, whose power consumption (P) was reduced by a factor of 18. The proposed device exhibited excellent mechanical stability, completing 100 consecutive bending operations without a noticeable reduction in TOS performance. For future emerging applications, these results open up novel possibilities for the creation and manufacturing of flexible optoelectronic systems, focusing on adaptable TOS solutions.

A simple thin-layer architecture based on epsilon-near-zero mode field enhancement is proposed for optical bistability in the near-infrared spectral range. The ultra-thin epsilon-near-zero material, characterized by its high transmittance and electric field energy confinement within its thin layer structure, greatly facilitates the interaction of input light, creating favorable circumstances for optical bistability within the near-infrared band.