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Published
, Published online: 23 September 2026
, doi: 10.37188/lam.2026.117
Multi-photon polymerization (MPP) is an emerging manufacturing method capable of producing highly detailed, arbitrarily shaped three-dimensional micro- and nanostructures with feature sizes of single elements below 100 nm. MPP conventionally relies on ultrashort pulse laser systems operating at peak powers in the kilowatt to tens of kilowatt regime and with peak intensities in the range of TW/cm2 to achieve sufficient nonlinear absorption. As a novel approach, here we demonstrate that lasers with significantly lower peak powers and lower peak intensities can also be utilized for MPP at high processing speeds, employing a novel monolithically integrated mode-locked diode laser with 30 W peak power, 7.7 ps pulse length, and a 13.2 GHz repetition rate which could achieve peak intensities of 23 GW/cm2. It is conceivable that the lower peak intensity may be partially compensated for by the considerably higher repetition rate. However, whether this type of compensation is applicable is unclear due to the inherent non-linear MPP process, and requires experimental verification in this work. Using this diode laser prototype, complex 3D structures at scan speeds of up to 100 mm/s were fabricated, achieving rapid production without compromising structural detail. Furthermore, the minimum achievable feature size was assessed through single-line scan experiments at various speeds, obtaining voxel dimensions of down to 121 nm in width and 151 nm in height. Our results suggest that diode laser-based MPP systems can deliver competitive processing performance with a more compact, much less complex, and more cost-effective laser source. This advancement paves the way for scalable parallel multi-laser MPP processing and may significantly accelerate the broader adoption of MPP technology.
Published
, Published online: 23 September 2026
, doi: 10.37188/lam.2026.070
Efficient terahertz (THz) wave manipulation is essential for advancing communications, imaging, and security detection. However, conventional THz devices based on natural materials suffer from the issues of bulky size, low efficiency, and narrow bandwidth. Although dielectric metasurfaces offer a promising alternative, their practical applications still face challenges in high-precision manufacturing, particularly for structures with high aspect-ratio (AR) and deep etching depth. Herein, we experimentally construct high-quality silicon meta-devices for THz wave-controls. Guided by the analysis of the potential structural imperfections, we propose an optimized fabrication method based on the Bosch etching technology to address these challenges and create silicon meta-atoms with high AR and vertical sidewall. As a proof-of-concept, we design and fabricate a half-wave plate (HWP) and a quarter-wave plate (QWP) with a maximum AR of 19.2:1 and broad working bands (0.6–0.8 THz and 0.5–0.8 THz). Their polarization conversion ratios (PCRs) can reach 0.915 and 0.99 at approximately 0.73 THz and 0.66 THz, respectively. Furthermore, we experimentally realize a highly efficient and broadband metalens exhibiting the high average focusing efficiency of 85.56% within 0.6–0.8 THz. Our fabrication methodology can be extended to fabricate other high-performance metasurfaces, opening new possibilities for broadband THz applications.
Published
, Published online: 23 September 2026
, doi: 10.37188/lam.2026.100
As semiconductor process nodes advance, the interaction between electromagnetic waves and mask three-dimensional topography becomes increasingly significant. Curvilinear masks with superior process windows are being rapidly adopted, exposing the limitations of existing thick-mask models in accommodating arbitrary curvilinear edges. Therefore, a theoretical framework for the full-chip-scale, rapid modelling of curvilinear thick masks is required. This paper introduces a physically covariant curvilinear thick-mask model based on edge diffraction correction for rapid full-chip layout simulation. The model decomposes the mask response into a thin-mask approximation term and an edge diffraction correction term. Through rigorous mathematical derivation, the diffraction response of the reference mask edges is decomposed into physically meaningful two-dimensional differential edge diffraction kernels. Furthermore, the edge diffraction term of full-chip layouts is efficiently reconstructed via a multi-channel tensor convolution framework, thereby correcting the thin-mask approximation and establishing the curvilinear thick-mask model. Simulation results demonstrated that, compared with finite-difference time-domain benchmarks, the proposed model achieved curvilinear mask near-field root mean square errors below 0.03 while delivering a speed-up of over 2,600 times. Moreover, it provided more than 2× error reduction over traditional Manhattanisation curvilinear models and maintained superior physical covariance. This study is expected to provide robust support not only for efficient and accurate forward modelling in resolution-enhancement techniques, such as inverse lithography technology and source mask optimisation, but also for the optical characteristic fast simulation of metasurfaces and metamaterials.
Published
, Published online: 18 September 2026
, doi: 10.37188/lam.2026.095
Carbon materials have significant scientific and application potential in the terahertz field. Metasurfaces are considered the core components of next-generation of terahertz photonic systems. The introduction of advanced carbon-based fabrication techniques operating with high efficiency and low complexity is essential for the development of terahertz metasurface photonic devices. In this study, we demonstrate a carbon-based manufacturing approach. This relies on a dual-mode additive manufacturing technique and can be used to directly print subwavelength resonant structures on flexible substrates. We demonstrate the preparation method and properties of different carbon nanocomposite inks. In addition, we present printing parameter configurations and printing results. To demonstrate their effectiveness, two carbon-based metasurface terahertz absorbers and a terahertz filter are designed and fabricated. The resonant structures are printed directly onto different flexible substrates using different printing modes. A fibre-based terahertz spectroscopy system is built to test the samples. The test results meet the expectations and are consistent with the simulations. By enabling the low complexity of carbon-based additive manufacturing and offering flexibility in flexible substrate choice and resonant-pattern design, the approach could facilitate terahertz metasurface technologies for real-world applications.
Published
, Published online: 18 September 2026
, doi: 10.37188/lam.2026.107
Photonic integrated circuits (PICs) are expected to overcome the intrinsic bottleneck faced by conventional electronic circuits, enabling substantial improvements in bandwidth capacity and data processing speed. Nevertheless, the on-chip integration of lasers remains a critical challenge hindering the development of PICs. Furthermore, conventional photonic devices exhibit large feature sizes and inter-component separation distances on the order of tens of micrometres, resulting in a low integration density. In this study, an ultracompact integrated photonic logic chip is proposed for all-optical information processing. The integrated architecture comprises a III-V micro-laser, four hybrid Bi2Te3-Si micro-ring resonators, and inverse-designed structures. The nonlinear material Bi2Te3 coated on the Si micro-ring resonators achieved optical tunability. The components are interconnected via waveguides and inverse-designed structures with a compact intercomponent distance of merely 1.5 μm. Pump–probe measurements reveal hundreds of femtoseconds of transient responses in the hybrid Bi2Te3-Si resonant elements, whereas the integrated chip experimentally demonstrates two-bit optical logic operations enabled by the hybrid resonators and integrated micro-laser. This study presents a novel technical solution for the implementation of fully on-chip integrated photonic circuits and establishes a new research paradigm for the development of ultrahigh-integration-density photonic chips.
Published
, Published online: 18 September 2026
, doi: 10.37188/lam.2026.120
Efficient light harvesting from front and rear sides is essential for improving solar energy utilisation in applications such as photovoltaics and seawater desalination. This requires absorbers that exhibit strong double-sided absorption in the ultraviolet to near-infrared range, mechanical flexibility for transfer onto diverse substrates, reliable performance stability, and manufacturing scalability for practical deployment. However, these capabilities are difficult to achieve simultaneously using conventional thin-film or metamaterial absorbers. In this study, we developed a double-sided bioinspired metamaterial absorber (DS-BMA) composed of a single layer of chromium (Cr) nano-units, whose front and back surfaces mimic the morphologies of moth eyes and marine diatoms, respectively. The gradient geometric configuration of the DS-BMA significantly broadened the bandwidths of plasmonic resonances, thereby enabling near-perfect absorption over the entire solar spectrum. Using a scalable self-assembly-based process, we experimentally showed a flexible, transferable DS-BMA with a thickness of 500 nm. It achieved average absorptances of 93% and 96% on the front and back sides, respectively, over a wavelength range of 220–2,500 nm. The DS-BMA exhibited polarisation-independent omnidirectional absorption as well as excellent thermal stability, corrosion resistance, and mechanical robustness. Therefore, the DS-BMA provides a promising route toward high-efficiency, low-cost, and integrable photothermal/photovoltaic energy conversion devices.
Published
, Published online: 16 September 2026
, doi: 10.37188/lam.2026.128
Additive manufacturing using 2-Photon Polymerization (2PP, aka direct laser writing DLW) enables the fabrication of almost arbitrary complex 3D structures from the meso to the sub-micron scale. However, deviations between the anticipated target structure and the actual print often occur due to physico-chemical processes, limiting the accuracy and reliability of this technology. To minimize these deviations, we hereby present our latest research in developing different neural networks, targeting the above-mentioned aspect. Our networks are trained on several experimental as well as theoretical datasets and show good results in predicting fabrication deviations and (pre-) correcting 2.5D μ-structures. Hence, we demonstrate, that besides conventional iterative correction methods, neural networks are a promising alternative to significantly improving the output quality in DLW. First directly pre-corrected structures show a reduction of the root mean square error up to 93% in the best case scenario. Furthermore, there are no fundamental limitations to transferring this machine learning approach to other 3D printing technologies, as they all face the same challenge in terms of fidelity. To our point of view, the use of neural networks has the potential to enhance the capabilities of this technology, enabling the creation of complex structures with increased accuracy and precision in the near future.
Published
, Published online: 09 September 2026
, doi: 10.37188/lam.2026.112
Table-top extreme ultraviolet (EUV) reflection ptychography has gained increasing interest in semiconductor metrology due to its nanometer-scale resolution, nondestructive character, and laboratory-scale cost-effectiveness. However, its widespread adoption remains constrained by alignment challenges inherent to grazing-reflection geometry, which have prevented reflective configurations from achieving image quality comparable to those of transmission-mode systems. In this study, we introduce a table-top EUV grazing-reflection ptychography system that enables full-pose self-calibration through holistic system modeling and highly efficient optimization. The developed system is validated using a customized wafer sample and real chip sample. Experimental results indicate that the system successfully corrects image distortions, improves resolution, and enhances surface metrology quality. Furthermore, we discuss algorithmic and physical issues including the feature-domain phase-retrieval for ptychography and coupling effect among pose parameters. The proposed approach not only accelerates the transition of EUV reflection ptychography toward real-world use but also opens avenues for methodological advances to a wider range of imaging applications.
Published
, Published online: 08 September 2026
, doi: 10.37188/lam.2026.090
Phase-shifting interferometry underpins surface topography metrology in precision fields such as semiconductor manufacturing and optical engineering. However, its reliance on stringent vibration isolation and precise phase-shifting control restricts its applicability in many scenarios, particularly in the characterisation of large-aperture optical components. To address these limitations, we present disturbance-introduced interferometry, which harnesses ambient random mechanical disturbances as phase-shifting sources. We also develop a large-disturbance-adaptive natural phase decoding algorithm to reconstruct the surface topography from the resulting interferograms. This framework reduces reliance on stringent vibration isolation and precise phase-shifting control, making it particularly suitable for large-aperture surface metrology and measurements in vibration-prone manufacturing environments. Experimental results demonstrated that even in uncontrolled and vibration-prone environments, the method achieves a root-mean-square wavefront repeatability below 0.0018\begin{document}$ \lambda $\end{document} \begin{document}$ \lambda $\end{document} \begin{document}$ \lambda $\end{document} \begin{document}$ \lambda $\end{document} \begin{document}$ \lambda $\end{document}
Published
, Published online: 07 September 2026
, doi: 10.37188/lam.2026.105
An achromatic metalens (480–640 nm) was designed via integrating propagation and geometric phase principles and fabricated using one-step nanoimprint lithography (NIL). A novel nanoimprint photoresist was used, which not only has a high refractive index (1.92–1.97) and high transmittance (>99%) but also exhibits low shrinkage (≤5.19%). This low shrinkage results in small dimensional deviations of the meta-atoms relative to the NIL master. The working stamp was fabricated in 10 min using an ultraviolet-curable material. This process is much faster than polydimethylsiloxane-based alternatives, which require several hours of thermal curing. Owing to its high fabrication accuracy, the metalens exhibited excellent focusing and achromatic performance, with a wavelength-dependent focal-length deviation of <2%. This study has provided a potential route for the high-precision, high-efficiency, and large-scale production of achromatic metalenses and other nano/micro-optical devices.
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