Fengzhou Fang

With the widespread application of two-dimensional (2D) materials in ultrafast electronics and micro-nano optical devices, their stability and phase response under strong light fields have become crucial for device performance. Resonant coupling provides an effective pathway to tailor both amplitude and phase responses in atomically thin systems. However, a systematic understanding of substrate-mediated regulation of the optical field distribution and phase modulation in 2D materials remains limited. Taking MoS ₂ as a representative 2D material, this work investigates the effect of the substrate on optical amplitude modulation and phase response. By engineering the substrate structure, the optical intensity in MoS ₂ and reflection phase can be effectively tailored, enabling a reflection phase shift approaching π radians. Based on this effect, a Fresnel lens is fabricated on monolayer MoS ₂ , achieving sub-diffraction-limited focusing with a focal spot size of approximately 0.8 Airy units. These findings reveal the coupling between substrate-induced resonances, near-field reconstruction, and phase modulation in 2D systems, offering a pathway toward high-efficiency wavefront shaping and integrated nanophotonic devices.

Transferring gaze estimation models from mobile terminals to in-vehicle driving scenarios faces challenges from differences in device form, viewpoint, and imaging conditions. To address this, this study proposes a cross-scene adaptation framework that integrates composite multi-stage transfer learning with distributed multi-camera fusion for personalized in-vehicle gaze estimation. The framework builds upon a multi-level information element fusion baseline (MIEF) and explores three transfer paths (CMP1–CMP3) for progressive personalized adaptation from a large-scale mobile source domain to an in-vehicle target scenario. A distributed multi-camera platform is established, producing gaze calibration data (GCD) for cross-session training and driving gaze and road scene data (DRD) for visualization validation. A Multi-Camera Fusion Model (MCF) is designed with two paradigms, MCF-Lite and MCF-Plus, to balance accuracy improvement and computational complexity. Experimental results demonstrate that the composite multi-stage transfer learning path CMP3 achieves an average error of 0.277 across camera views, with a best single-camera mean error of 0.244. Building on this, the distributed MCF-Plus model with the full C1 + C2 + C3 configuration further reduces the mean error to 0.160 and the standard deviation to 0.127, with 96.88% of predicted gaze points falling within the target calibration block (Error < 0.5). The proposed method provides a feasible technical pathway for personalized adaptation of gaze estimation models from mobile-terminal source domains to in-vehicle multi-camera target scenarios, and offers preliminary experimental evidence for gaze behavior perception and driving gaze heatmap generation in real environments.

Recent optical force research has extended from microscopic manipulation to the actuation of macroscopic optical devices, for which multilayered dielectric-coated reflectors provide important platforms for studying optical-force-induced displacement. Such responses are commonly interpreted primarily in terms of incident optical power under near-normal incidence. However, under oblique incidence, the distinct boundary conditions and intralayer electromagnetic-field distributions of TE/TM polarizations cause the optical force distribution to depend on both incidence angle and polarization state. In this study, we investigate a SiO ₂ /ZrO ₂ multilayered dielectric mirror excited by a 527 nm pulsed laser at incidence angles of 15 ^∘ and 45 ^∘ under five calibrated polarization states. CWT/ICWT analysis identifies a reproducible high-frequency displacement band at 245-295 kHz. Its interpretation as a characteristic spectral signature of the optical-force-driven mechanical-mode response is supported by the 247.7 kHz reference mechanical frequency and a strongly coupled three-dimensional mode near 246.21 kHz. Across the paired excitation conditions, the peak displacement in this band increases with the corresponding single-pulse energy and is larger at 15 ^∘ than at 45 ^∘ . The normalized response also exhibits polarization-dependent modulation, with the polarization sensitivity increasing from 5.742% at 15 ^∘ to 11.727% at 45 ^∘ and a bootstrap-estimated difference of 5.985% (95% CI: 2.935-8.826%). These results provide experimental evidence for angle- and polarization-dependent optical-force responses in multilayered dielectric mirrors and highlight the importance of controlling incidence angle and polarization in macroscopic optical-force measurements.

Microscale surface textures (e.g., microgrooves, dimples, pillars) play a crucial role in tribology, optics, biomedical devices, and micro-electro-mechanical systems. Among various microfabrication technologies, micro-electrical discharge machining (micro-EDM) stands out as a cost-effective method for the fabrication of these surface textures with high accuracy. However, despite the rapid advancements in this field in recent years, a comprehensive and targeted review of micro-EDM for functional surface texturing is currently lacking in the literature. To address this gap, this paper systematically reviews recent progress in micro-EDM texturing across four major application areas: cutting tools, bioimplants, surgical instruments and mold components. For each field of application, the functional mechanisms, achievable surface features, demonstrated performance improvements, and existing technical challenges of micro-EDM are critically discussed and analyzed. Furthermore, current limitations and recommended future research directions are elaborated. This review provides valuable insights and practical guidance for advancing micro-EDM surface texturing and offers a roadmap for its broader adoption in industrial applications.