A decrease of up to 53% in the model's verification error range is achieved. By improving the efficiency of OPC model construction, pattern coverage evaluation methods contribute favorably to the complete 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. This paper introduces a flexible strain sensor utilizing FSS reflection characteristics. This sensor can conformally adhere to an object's surface, enduring mechanical deformation under load. Should the FSS structure be altered, the established working frequency will be displaced. By tracking the difference in electromagnetic capabilities, a real-time evaluation of the object's strain is achievable. This study details an FSS sensor design for a 314 GHz operating frequency and a -35 dB amplitude, exhibiting favorable resonance properties in the Ka-band. The quality factor of 162 in the FSS sensor is a strong indicator of its superb sensing ability. Strain detection in a rocket engine case, using statics and electromagnetic simulations, involved the application of the sensor. The analysis found a 200 MHz shift in the sensor's working frequency when the engine casing experienced a 164% radial expansion. The shift is directly proportional to the deformation under various loads, allowing for precise strain quantification of the engine case. Our study involved a uniaxial tensile test of the FSS sensor, utilizing experimental findings. The sensitivity of the sensor reached 128 GHz/mm when the FSS was stretched between 0 and 3 mm during the test. Ultimately, the high sensitivity and considerable mechanical strength of the FSS sensor support the practical benefits of the FSS structure designed in this research. STZ inhibitor price This field offers substantial room for development.

In long-haul, high-speed dense wavelength division multiplexing (DWDM) coherent systems, the cross-phase modulation (XPM) effect, triggered by the implementation of a low-speed on-off-keying (OOK) optical supervisory channel (OSC), adds to the nonlinear phase noise, consequently reducing the achievable transmission distance. We present, in this paper, a basic OSC coding method designed to address OSC-induced nonlinear phase noise. STZ inhibitor price By utilizing the split-step solution of the Manakov equation, the OSC signal's baseband is moved out of the walk-off term's passband, thereby leading to a reduction in the XPM phase noise spectrum 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. Idler pulses absorbing Sm3+ at a pump wavelength near 1 meter allow QPCPA for femtosecond signal pulses centered at 35 or 50 nanometers, achieving a conversion efficiency near the theoretical quantum limit. Due to the prevention of back conversion, mid-infrared QPCPA displays a high degree of resilience to both phase-mismatch and fluctuations in pump intensity. Employing the SmLGN-based QPCPA, a highly efficient means of transforming intense laser pulses currently well-developed at 1 meter to mid-infrared ultrashort pulses is provided.

This paper establishes a narrow linewidth fiber amplifier, constructed using a confined-doped fiber, and explores the amplifier's power scaling and beam quality maintenance characteristics. The large mode area of the confined-doped fiber, coupled with precise control over the Yb-doped region within the core, effectively balanced the stimulated Brillouin scattering (SBS) and transverse mode instability (TMI) effects. By capitalizing on the advantages of confined-doped fiber, a near-rectangular spectral injection, and the 915 nm pumping method, a laser signal outputting 1007 W with a 128 GHz linewidth is obtained. This result, as far as we know, is the first to exceed the kilowatt-level in all-fiber lasers, showcasing GHz-level linewidths. It could function as a valuable reference for synchronously controlling the spectral linewidth and managing stimulated Brillouin scattering (SBS) and thermal management issues (TMI) within high-power, narrow-linewidth fiber lasers.

A high-performance vector torsion sensor, designed using an in-fiber Mach-Zehnder interferometer (MZI), is proposed. The sensor includes a straight waveguide, which is inscribed within the core-cladding boundary of the standard single-mode fiber (SMF) by a single femtosecond laser inscription step. The fabrication of a 5-millimeter in-fiber MZI completes in under one minute. High polarization dependence in the device is a consequence of its asymmetric structure, as seen by the transmission spectrum's deep polarization-dependent dip. Torsion detection is possible by observing the polarization-dependent dip in the in-fiber MZI, since the input light's polarization state changes with the fiber's twist. Employing the wavelength and intensity of the dip, torsion demodulation is possible, and vector torsion sensing is accomplished by the precise selection of the incident light's polarization state. Intensity modulation yields a torsion sensitivity of 576396 dB per radian per millimeter. Variations in strain and temperature produce a subdued effect on dip intensity. The incorporated MZI design, situated within the fiber, keeps the fiber's coating intact, thereby sustaining the complete fiber's ruggedness.

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. Under the influence of double optical feedback (DOF), mutually coupled spin-polarized vertical-cavity surface-emitting lasers (MC-SPVCSELs) are investigated for their ability to generate optical chaos to facilitate permutation and diffusion-based encryption of 3D point clouds. The demonstration of nonlinear dynamics and complex results showcases that MC-SPVCSELs with DOF exhibit high chaotic complexity, yielding an exceptionally large key space. The ModelNet40 dataset, with its 40 object categories, underwent encryption and decryption using the proposed method for all its test sets, and the PointNet++ analyzed and listed the complete classification results for the original, encrypted, and decrypted 3D point clouds for each of the 40 categories. Intriguingly, the encrypted point cloud's class accuracies exhibit nearly uniform zero percent values, with the notable exception of the plant class, achieving a phenomenal one million percent. This outcome signifies the encrypted point cloud's unclassifiable and unidentified nature. There is a striking similarity between the accuracies of the decryption classes and those of the original classes. Thus, the classification results provide compelling evidence of the practical applicability and remarkable effectiveness of the proposed privacy protection system. Significantly, the outcomes of encryption and decryption processes indicate that the encrypted point cloud images are ambiguous and cannot be identified, whereas the decrypted point cloud images perfectly correspond to their original counterparts. The paper additionally elevates the security analysis through an examination of the geometrical features presented in 3D point clouds. In the end, various security analyses confirm the proposed privacy-focused strategy possesses a high security level and robust privacy protection for the task of classifying 3D point clouds.

The strained graphene-substrate system is predicted to exhibit the quantized photonic spin Hall effect (PSHE) under the influence of a sub-Tesla external magnetic field, significantly less potent than the magnetic field required in traditional graphene-substrate setups. Quantized behaviors of in-plane and transverse spin-dependent splittings in the PSHE are demonstrably different, exhibiting a strong relationship with reflection coefficients. While quantized photo-excited states (PSHE) in a standard graphene platform are a product of real Landau level splitting, the equivalent phenomenon in a strained graphene substrate is linked to pseudo-Landau level splitting, which is further complicated by the pseudo-magnetic field's influence. This pseudo-Landau level splitting is complemented by the lifting of valley degeneracy in the n=0 pseudo-Landau levels, a result of sub-Tesla external magnetic fields. As the Fermi energy evolves, the pseudo-Brewster angles of the system are correspondingly quantized. Quantized peak values of the sub-Tesla external magnetic field and the PSHE are observable near these angles. The giant quantized PSHE is foreseen to enable direct optical measurements of quantized conductivities and pseudo-Landau levels in the monolayer strained graphene.

Polarization-sensitive narrowband photodetection in the near-infrared (NIR) spectrum is increasingly important for optical communication, environmental monitoring, and the development of intelligent recognition systems. In contrast to the goal of on-chip integration miniaturization, current narrowband spectroscopy techniques frequently require extra filters or bulky spectrometers. The optical Tamm state (OTS), a recent discovery within topological phenomena, has provided a groundbreaking method for designing functional photodetectors. To the best of our knowledge, we have been the first to experimentally construct a device based on the 2D material graphene. STZ inhibitor price Infrared photodetection, sensitive to polarization and narrowband, is shown in OTS-coupled graphene devices, with the utilization of the finite-difference time-domain (FDTD) method for their design. The tunable Tamm state facilitates the narrowband response of the devices at NIR wavelengths. The observed full width at half maximum (FWHM) of the response peak stands at 100nm, but potentially increasing the periods of the dielectric distributed Bragg reflector (DBR) could lead to a remarkable improvement, resulting in an ultra-narrow FWHM of 10nm.