This purely numerical study develops a correlation-aware framework for quantifying fabrication-induced uncertainty in a dual one-dimensional photonic-crystal refractive-index sensor; no device was fabricated, and no spectrum was measured. The geometry-error model is prescribed rather than measured: Layer-specific thickness errors have a relative standard deviation of 0.5%, a global thickness-scale error of 0.3% is shared exactly by both channels, and matched layer-specific errors have a cross-channel correlation of 0.90. A verified transfer-matrix model is combined with finite-difference Jacobians, covariance propagation, bounded candidate screening, and paired full-spectrum Monte Carlo simulation. The original 300-design pool was frozen, and nested stratified/LHS-style expansions were used to construct 500- and 1000-design pools in three independent expansion replicates. The expanded pools retained the same maximum-figure-of-merit (FOM) endpoint and showed only small changes at the low-variability endpoint, while denser sampling resolved the intermediate trade-off and the more restrictive variability-ratio-constrained portion of the sampled trade-off more clearly. Seventeen representatives chosen by prespecified rules were refined with 900 paired Monte Carlo realizations each, and six designs (F0–F5) were then validated with five independent random seeds with 1000 paired realizations per seed, giving 5000 paired realizations per design. Among the six validated designs, F1 had the smallest differential wavelength standard deviation, with a baseline-normalized ratio of 0.9500 (95% bootstrap confidence interval: 0.9256–0.9743). Among the six validated designs, F3 combined a nominal FOM of 1152.25 RIU−1 with a wavelength-variability ratio of 0.9728 (0.9489–0.9979), while among the six validated designs, F5 reached the largest nominal FOM, 1303.55 RIU−1, and the smallest sensitivity-normalized equivalent refractive-index uncertainty ratio, 0.8849 (0.8626–0.9077). The correlation threshold of about 0.5 for layer errors follows algebraically from the near symmetry of the two channels and is not a design constant; the design information lies in the Jacobians, the covariance structure, and the resulting absolute uncertainty. All quantitative conclusions are therefore conditional on the prescribed optical and fabrication models.
Quartz glass is widely used in semiconductor quartz ware owing to its excellent thermal stability, optical transmittance, chemical resistance, and mechanical durability, and a major manufacturing technology to fabricate those semiconductor quartz wares is manual torch–based welding. However, welding defects, such as voids and cracks, can occur during manual torch–based quartz glass welding, potentially causing particle generation and process reliability issues in semiconductor manufacturing. In this study, optical coherence tomography (OCT) was applied as a nondestructive inspection technique to detect internal defects in quartz glass welds. Two quartz glass plates were welded at an angle of 120° using a torch-based flame-welding process, and three defective regions were examined. Optical microscopy (OM) was used to identify the actual defect positions and depths, and the OCT results were compared with OM observations. OCT successfully detected internal welding defects at the depths of approximately 3.99–4.20 mm, which were comparable to the focal depths measured using OM. The effect of scan speed was also evaluated at 2, 5, and 10 mm/s. Although large defects were detected at higher scan speeds, the OCT signal intensity and defect detectability decreased with increasing scan speed. These results demonstrate the feasibility of OCT-based nondestructive inspection for the detection of internal defects in quartz glass welding.
For practical underwater wireless communication links, one significant challenge is the random fluctuation of turbulence that will affect the link performance. In this work, we employ autofocusing Airy vortex beams (AAVBs) to characterize and mitigate oceanic turbulence, and the corresponding channel capacity in turbulent ocean is investigated. The most notable feature of AAVBs in turbulent ocean is the abrupt autofocus under the combined effects of self-healing and self-focusing, which leads to a complicated evolving behavior of the channel information capacity with propagation distance. Unlike nonautofocusing vortex beams, whose channel capacity monotonically declines with propagation distance in oceanic turbulence, the channel capacity of AAVB-based links follows a decrease–increase–decrease pattern, corresponding, respectively, to the self-accelerating, autofocusing, and diffusion regimes. Furthermore, three optical parameters related to the channel capacity of oceanic turbulence, i.e., topological charge (TC), radius of the primary ring, and exponential decaying factor, are discussed in detail. It indicates that AAVBs are better light sources’ candidates for mitigating the influences of oceanic turbulence on channel capacity and offers the possibilities to improve the channel capacity of optical vortex communication systems in underwater communication.
In this work, we present a polarization-sensitive imaging photodetector based on a PdSe2/MoS2 van der Waals heterojunction. Capitalizing on the strong anisotropic optoelectronic characteristics of the heterostructure, the device exhibits exceptional polarization-resolved imaging capabilities across the visible to near-infrared spectrum. It achieves a high polarization extinction ratio of 3.64 at 532 nm, enabling precise polarization discrimination in imaging applications. The detector further demonstrates robust performance in polarization-based contrast enhancement and scene analysis. These results underscore the significant potential of the PdSe2/MoS2 heterojunction for next-generation polarization-sensitive imaging systems operating in broad spectral ranges.
In this work, we present a polarization‐sensitive imaging photodetector based on a PdSe 2 /MoS 2 van der Waals heterojunction. Capitalizing on the strong anisotropic optoelectronic characteristics of the heterostructure, the device exhibits exceptional polarization‐resolved imaging capabilities across the visible to near‐infrared spectrum. It achieves a high polarization extinction ratio of 3.64 at 532 nm, enabling precise polarization discrimination in imaging applications. The detector further demonstrates robust performance in polarization‐based contrast enhancement and scene analysis. These results underscore the significant potential of the PdSe 2 /MoS 2 heterojunction for next‐generation polarization‐sensitive imaging systems operating in broad spectral ranges.
