A reduction of up to 53% occurs in the verification error range of the model. OPC model building efficiency is enhanced by the application of pattern coverage evaluation methodologies, which in turn contributes to the overall effectiveness of the OPC recipe development process.

Frequency selective surfaces (FSSs), characterized by their superior frequency selection capabilities, hold tremendous potential for applications in engineering, showcasing their value as modern artificial materials. A novel flexible strain sensor, utilizing FSS reflection, is detailed in this paper. This sensor's conformal attachment to an object allows for the endurance of mechanical deformation stemming from a load applied to it. A modification in the FSS structure invariably results in a shift of the initial operational frequency. In real-time, the strain magnitude of an object is determinable through the measurement of discrepancies in its electromagnetic behavior. This study presents an FSS sensor operating at 314 GHz, characterized by a -35 dB amplitude and displaying favourable resonance within the Ka-band. The FSS sensor's sensing performance is remarkable, evidenced by its quality factor of 162. Strain detection in a rocket engine case, using statics and electromagnetic simulations, involved the application of the sensor. The analysis demonstrates that a 164% radial expansion of the engine case caused a roughly 200 MHz shift in the sensor's working frequency. The linear relationship between the frequency shift and the deformation under varying loads enables accurate strain measurement of the case. Based on the results of our experiments, a uniaxial tensile test was conducted on the FSS sensor within this study. Testing revealed a sensor sensitivity of 128 GHz/mm when the flexible structure sensor (FSS) was stretched between 0 and 3 mm. Ultimately, the high sensitivity and considerable mechanical strength of the FSS sensor support the practical benefits of the FSS structure designed in this research. check details This area of study presents vast opportunities for development.

The cross-phase modulation (XPM) phenomenon, characteristic of long-haul, high-speed dense wavelength division multiplexing (DWDM) coherent systems, results in additional nonlinear phase noise when a low-speed on-off-keying (OOK) optical supervisory channel (OSC) is used, consequently diminishing transmission reach. We present, in this paper, a basic OSC coding method designed to address OSC-induced nonlinear phase noise. check details The Manakov equation's split-step solution involves up-converting the OSC signal's baseband, relocating it beyond the walk-off term's passband, thereby decreasing the XPM phase noise spectral density. The 1280 km transmission of the 400G channel shows a 0.96 dB boost in optical signal-to-noise ratio (OSNR) budget in experimental results, achieving practically the same performance as the scenario without optical signal conditioning.

Numerical analysis reveals highly efficient mid-infrared quasi-parametric chirped-pulse amplification (QPCPA) using a novel Sm3+-doped La3Ga55Nb05O14 (SmLGN) crystal. QPCPA for femtosecond signal pulses centered at 35 or 50 nanometers is enabled by the broadband absorption of Sm3+ in idler pulses at a pump wavelength near 1 meter, with conversion efficiency nearing the quantum limit. Mid-infrared QPCPA demonstrates robustness against phase-mismatch and pump-intensity variation precisely because of the suppression of back conversion. The SmLGN-based QPCPA will effectively convert well-established, intense laser pulses at 1 meter wavelength to mid-infrared, ultrashort pulses.

This manuscript investigates a narrow linewidth fiber amplifier, realized using a confined-doped fiber, evaluating its power scaling capabilities and beam quality preservation. The confined-doped fiber, with its large mode area and precisely controlled Yb-doped region within the core, successfully managed the interplay between stimulated Brillouin scattering (SBS) and transverse mode instability (TMI). Employing a combination of confined-doped fiber, near-rectangular spectral injection, and 915 nm pumping, a 1007 W signal laser is realized, showcasing a linewidth of only 128 GHz. This result, as far as we are aware, represents the first instance of an all-fiber laser demonstration exceeding the kilowatt level in conjunction with GHz-level linewidths. It could serve as a benchmark for effectively managing spectral linewidth, minimizing stimulated Brillouin scattering, and controlling thermal management issues in high-power, narrow-linewidth fiber lasers.

We posit a high-performance vector torsion sensor, utilizing an in-fiber Mach-Zehnder interferometer (MZI), structured from a straight waveguide precisely etched within the core-cladding boundary of the standard single-mode fiber (SMF) in a single femtosecond laser inscription step. A one-minute fabrication process yields a 5-millimeter in-fiber MZI. The asymmetric configuration of the device is responsible for its strong polarization dependence, directly reflected in the transmission spectrum's pronounced polarization-dependent dip. Torsion sensing is facilitated by the varying polarization state of the incoming light into the in-fiber MZI, which is influenced by fiber twist, and monitored by the polarization-dependent dip. By controlling both the wavelength and intensity of the dip, torsion can be demodulated, and vector torsion sensing can be achieved by adjusting the polarization state of the incoming light beam. The intensity modulation method showcases a torsion sensitivity that reaches 576396 dB/(rad/mm). Variations in strain and temperature produce a subdued effect on dip intensity. Moreover, the integrated Mach-Zehnder interferometer within the fiber preserves the fiber's protective coating, thereby ensuring the structural integrity of the entire fiber assembly.

This paper proposes and implements a novel optical chaotic encryption scheme for 3D point cloud classification, thereby providing a first-time solution to the critical issues of privacy and security that affect this field. Investigations of mutually coupled spin-polarized vertical-cavity surface-emitting lasers (MC-SPVCSELs) under double optical feedback (DOF) are conducted to exploit optical chaos for the encryption process of 3D point cloud data using permutation and diffusion. Evidence from the nonlinear dynamics and complexity analysis strongly suggests that MC-SPVCSELs, featuring degrees of freedom, exhibit high chaotic complexity, contributing to a very large key space. The proposed scheme encrypts and decrypts all test sets of the ModelNet40 dataset, which encompasses 40 object categories, and subsequently, the PointNet++ enumerates all classification results of the original, encrypted, and decrypted 3D point clouds for these 40 object categories. It is noteworthy that the classification accuracies of the encrypted point cloud are almost exclusively zero percent, with the exception of the plant class, where the accuracy reached a striking one million percent. This points to the encrypted point cloud's inability to be effectively classified and identified. There is a striking similarity between the accuracies of the decryption classes and those of the original classes. The classification results, in effect, exemplify the practical usability and remarkable effectiveness of the presented privacy protection model. Furthermore, the encryption and decryption processes reveal that the encrypted point cloud images lack clarity and are indecipherable, whereas the decrypted point cloud images precisely match the original ones. This paper enhances security analysis by scrutinizing the geometric features extracted from 3D point clouds. Through comprehensive security analysis, the proposed privacy-enhancing strategy demonstrates a high level of security and strong privacy protection capabilities for 3D point cloud classification.

Within a strained graphene-substrate configuration, the quantized photonic spin Hall effect (PSHE) is predicted to materialize under the impact of a sub-Tesla external magnetic field, a substantially weaker magnetic field than conventionally required for the effect within the graphene-substrate system. Analysis reveals distinct quantized behaviors in the in-plane and transverse spin-dependent splittings within the PSHE, exhibiting a close correlation with reflection coefficients. The quantized photo-excited states (PSHE) observed in a typical graphene-substrate setup are attributed to the splitting of real Landau levels. In contrast, the PSHE quantization in a strained graphene substrate is a complex phenomenon arising from the splitting of pseudo-Landau levels associated with a pseudo-magnetic field. The lifting of valley degeneracy in n=0 pseudo-Landau levels, influenced by sub-Tesla external magnetic fields, further contributes to this quantization. Simultaneously, the pseudo-Brewster angles of the system undergo quantization alongside fluctuations in Fermi energy. The quantized peak values of both the sub-Tesla external magnetic field and the PSHE appear prominently near these angles. The monolayer strained graphene's quantized conductivities and pseudo-Landau levels are predicted to be directly measurable using the giant quantized PSHE.

The near-infrared (NIR) region has seen a surge in interest for polarization-sensitive narrowband photodetection in applications such as optical communication, environmental monitoring, and intelligent recognition systems. Although narrowband spectroscopy presently heavily depends on external filters or bulky spectrometers, this approach conflicts with the goal of on-chip integration miniaturization. Topological phenomena, including the optical Tamm state (OTS), have opened up new pathways for the development of functional photodetectors. We, to the best of our knowledge, are the first to experimentally construct a device based on the 2D material, graphene. check details Polarization-sensitive narrowband infrared photodetection is demonstrated in OTS-coupled graphene devices, employing the finite-difference time-domain (FDTD) method in their design. The devices' narrowband response at NIR wavelengths is a consequence of the tunable Tamm state. Given the current full width at half maximum (FWHM) of 100nm in the response peak, increasing the periods of the dielectric distributed Bragg reflector (DBR) could potentially produce an ultra-narrow FWHM of approximately 10nm.