Optical Diffraction Research Articles

Exploring the Effects of Open-Air Cooling on the Formation of Microstructure in Cast A356 Aluminum Alloy

The lightweight composition, non-magnetic nature, and machinability of aluminum alloy A356 make it an important material in many industries due to its significant mechanical properties such as strength, ductility, fatigue resistance, and castability. Aluminium alloy forms an oxide layer when exposed to air. The microstructure of this alloy plays a critical role in determining its mechanical behavior. This study utilized aluminum alloy A356, composed of 92.05% aluminum, 7% silicon, 0.35% magnesium, 0.20% copper, 0.10% manganese, and 0.10% zinc. This alloy exhibits extremely high corrosion resistance, similar to stainless steel, with a melting point of 650°C. The study examines multi- component (mainly Al with Si) A356 containing small amounts of Mg, Cu, Mn, and Zn for their complex microstructural behavior. It includes observations using techniques such as optical microscopy and X-ray diffraction (XRD). This research was carried out to investigate different areas of the same metal’s microstructure and to discover the influence of cooling rates during the solidification process. The findings revealed that there are dissimilarities between the central parts and outer areas, as well as similarities between the two side portions. Also, this study highlights processing conditions’ impact on the material response while looking at heat transfer rate effects during solid-state transformation. The findings of this study highlight the presence of distinct microstructures (dendritic and equiaxed structures) across different sections of the cast Aluminum alloy A356. These findings contribute to a better understanding of the microstructure-property relationship of Aluminum alloy A356, assisting in improvising design and manufacturing processes for enhanced performance.

Optical diffraction tomography using a self-reference module

Optical diffraction tomography enables label-free, 3D refractive index (RI) imaging of biological samples. We present a novel, cost-effective approach to ODT that employs a modular design incorporating a self-reference holographic capture module. This two-part system consists of an illumination module and a capture module that can be seamlessly integrated with any life-science microscope using an automated alignment protocol. The illumination module employs a galvo-scanner system, providing precise control over the angular illumination, while the capture module utilises the principle of self-reference off-axis holography. The design has a compact form factor, simple alignment, and reduced cost. Furthermore, our system offers the capability to switch between two imaging modalities, ODT and real-time synthetic aperture digital holographic microscopy (SA-DHM), a unique feature not found in other setups. Experimental results are provided using a kidney cancer cell line. Experimental results are provided using a kidney cancer cell line.

Effects of particle sizes and roasting temperature on the Fe-Ni enrichment of limonite ore from the Wolo mine area, Southeast Sulawesi, using corncob char as reductant

Abstract The reduction roasting of a limonite ore sample from the Wolo mine area was investigated using corncob char as a reductant. The objectives of this study were to analyze the effects of particle sizes and roasting temperature on the mineralogical transformation and Fe-Ni enrichment during the roasting process. The limonite ore was prepared into three size fractions of mesh sieves (-100+150, -150+200, and -200 mesh). Limonite ore was roasted with 2g of corn cob char reductant at temperatures ranging between 800 °C and 1100 °C with a 1-hour reduction time. Limonite ore and roasted products were analyzed to determine the mineral and chemical composition using optical microscopy, X-ray diffraction (XRD), and X-ray fluorescence (XRF) methods. Results of the mineralogical analysis indicated that the sample contained chlorite, goethite, lizardite, maghemite, and quartz. Limonite ore is mainly composed of Fe2O3 (53.59%), followed by SiO2 (12.16%), MgO (2.63%), and Ni (1.52%). Results of reduced roasting of limonite ore exhibited that the ore minerals were transformed into spinel, wustite, fayalite, and some tetrataenite (FeNi). The ore with -100+150 mesh particle and heated at 1,000 °C provided the optimum enrichment of 1.74% Ni and 42.87% Fe, respectively.

Insights into an indolicidin-derived low-toxic anti-microbial peptide's efficacy against bacterial cells while preserving eukaryotic cell viability.

Antimicrobial peptides (AMPs) are a current solution to combat antibiotic resistance, but they have limitations, including their expensive production process and the induction of cytotoxic effects. We have developed novel AMP candidate (peptide 3.1) based on indolicidin, among the shortest naturally occurring AMP. The antimicrobial activity of this peptide is demonstrated by the minimum inhibitory concentration, while the hemolysis tests and MTT assay indicate its low cytotoxicity. In optical diffraction tomography, red blood cells treated with peptide 3.1 showed no discernible effects, in contrast to indolicidin. However, peptide 3.1 did induce cell lysis in E. coli, leading to a reduced potential for the development of antibiotic resistance. To investigate the mechanism underlying membrane selectivity, the structure of peptide 3.1 was analyzed using nuclear magnetic resonance spectroscopy and molecular dynamics simulations. Peptide 3.1 is structured with an increased distinction between hydrophobic and charged residues and remained in close proximity to the eukaryotic membrane. On the other hand, peptide 3.1 exhibited a disordered conformation when approaching the prokaryotic membrane, similar to indolicidin, leading to its penetration into the membrane. Consequently, it appears that the amphipathicity and structural rigidity of peptide 3.1 contribute to its membrane selectivity. In conclusion, this study may lead to the development of Peptide 3.1, a promising commercial candidate based on its low cost to produce and low cytotoxicity. We have also shed light on the mechanism of action of AMP, which exhibits selective toxicity to bacteria while not damaging eukaryotic cells.

Nanostructure-Dependent Electrical Conductivity Model Within the Framework of the Generalized Effective Medium Theory Applied to Poly(3-hexyl)thiophene Thin Films.

One of the key parameters characterizing the microstructure of a layer is its degree of order. It can be determined from optical studies or X-ray diffraction. However, both of these methods applied to the same layer may give different results because, for example, aggregates may contribute to the amorphous background in XRD studies, while in optical studies, they may already show order. Because we are usually interested in the optical and/or electrical properties of the layers, which in turn are closely related to their dielectric properties, determining the optical order of the layers is particularly important. In this work, the microstructure, optical properties and electrical conductivity of poly(3-hexyl)thiophene layers were investigated, and a model describing the electrical conductivity of these layers was proposed. The model is based on the generalized theory of the effective medium and uses the equation from the percolation theory of electrical conductivity for the effective medium of a mixture of two materials. The results indicate a key role of the aggregate size and limited conductivity of charge carriers, mainly due to structural imperfections that manifest themselves as an increase in the number of localized states visible in the subgap absorption near the optical absorption edge. The critical value of the order parameter and the corresponding values of the Urbach energy, excitonic linewidth and band gap energy are determined.

Nb impurity-bound excitons as quantum emitters in monolayer WS2

Point defects in crystalline solids behave as optically addressable individual quantum systems when present in sufficiently low concentrations. In two-dimensional (2D) semiconductors, such quantum defects hold potential as versatile single photon sources. Here, we report the synthesis and optical properties of Nb-doped monolayer WS2 in the dilute limit where the average spacing between individual dopants exceeds the optical diffraction limit, allowing the emission spectrum to be studied at the single-dopant level. We show that these individual dopants exhibit common features of quantum emitters, including narrow emission lines (with linewidths <1 meV), strong spatial confinement, and photon antibunching. These emitters consistently occur within a narrow spectral range across multiple samples, distinct from common quantum emitters in van der Waals (vdW) materials that show large ensemble broadening. Analysis of the Zeeman splitting reveals that they can be attributed to bound exciton complexes comprising dark excitons and negatively charged Nb.

Learned Multi-aperture Color-coded Optics for Snapshot Hyperspectral Imaging

Learned optics, which incorporate lightweight diffractive optics, coded-aperture modulation, and specialized image-processing neural networks, have recently garnered attention in the field of snapshot hyperspectral imaging (HSI). While conventional methods typically rely on a single lens element paired with an off-the-shelf color sensor, these setups, despite their widespread availability, present inherent limitations. First, the Bayer sensor's spectral response curves are not optimized for HSI applications, limiting spectral fidelity of the reconstruction. Second, single lens designs rely on a single diffractive optical element (DOE) to simultaneously encode spectral information and maintain spatial resolution across all wavelengths, which constrains spectral encoding capabilities. This work investigates a multi-channel lens array combined with aperture-wise color filters, all co-optimized alongside an image reconstruction network. This configuration enables independent spatial encoding and spectral response for each channel, improving optical encoding across both spatial and spectral dimensions. Specifically, we validate that the method achieves over a 5dB improvement in PSNR for spectral reconstruction compared to existing single-diffractive lens and coded-aperture techniques. Experimental validation further confirmed that the method is capable of recovering up to 31 spectral bands within the 429--700 nm range in diverse indoor and outdoor environments.

Impact of gradient zero-valent iron pollution from steel works on soil microaggregate geochemical processes and dissipative structures

Abstract: Zero-valent iron (ZVI) contamination from steel works poses significant threats to soil quality and ecosystem health, particularly affecting soil microaggregates, which are fundamental to soil structure and function. In this study, we systematically investigated the impact of gradient ZVI pollution on the organic geochemical environment of soil microaggregates around steel works located in the core water source area of the Middle Route of the South-to-North Water Diversion Project in China. Advanced analytical techniques, including X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray fluorescence spectroscopy (XRF), inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), were employed to comprehensively characterize the geochemical processes, mineralogy, and organic matter environment of soil microaggregates. The findings revealed that soils near the steel works were acidified and strongly oxidized, with heavy metal contents, particularly Fe, significantly decreasing with increasing distance from the steel works (Fe content decreased from 27,516.2 mg/kg to 23,492.6 mg/kg). The pH of soils near the steel works was lower, while oxidation-reduction potential (ORP) and electrical conductivity were higher. XPS analysis indicated a higher content of reactive oxygen species (ROS) near the steel works and significantly lower soil organic matter content. The iron valence distribution showed spatial differences, with higher Fe2⁺ content on the surface of soil microaggregates near the steel works and Fe³⁺ dominating in areas farther away. These results suggest an evolutionary sequence of ZVI from Fe (0) oxidation to Fe(II) and then to Fe(III). The formation of dissipative structures in soil microaggregates due to ZVI contamination significantly affects soil physicochemical properties and the organic environment. This study provides valuable insights into the multifaceted impacts of industrial activities on soil ecosystems and offers a scientific basis for soil conservation and remediation strategies.

Photoinduced Anisotropy in Thin Films of Azobenzene-Containing Liquid Crystalline Supramolecular Complexes of Various Polymer Architecture.

Light patternable colorless liquid crystalline (LC) polymers are promising materials for functional photonic devices with broad applications in optical communication, diffractive optics, and displays. This work reports photoinduced optical anisotropy in thin films of azobenzene-containing (Azo) LC block copolymer supramolecular complexes, which can be decolorized after light patterning providing colorless patterned birefringent polymer films. The supramolecular complexes are prepared via intermolecular pyridine-phenol hydrogen bonding between a low-molecular-weight Azo phenol and host LC AB diblock and ABA triblock copolymers consisted of LC phenylbenzoate (PhM) blocks and poly(vinylpyridine) units. The molecular architecture of the host polymers and the morphological pattern formed by the complexes can affect orientational behavior of Azo groups under irradiation with linearly polarized light. Photoorientation of hydrogen-bonded Azo groups is accompanied by the cooperative orientation of non-photochromic PhM units, which form individual microphases and stabilize the orientation of Azo groups. This effect is specific for block copolymer complexes and it is absent for random copolymer complex, which is used as a reference sample. Optical anisotropy induced in films of the block copolymer complexes can be amplified by heating above the glass transition temperature and subsequent rinsing with diethyl ether allows colorless birefringent polymer films to be prepared.

Investigations on Microstructure, Mechanical, and Wear Properties, with Strengthening Mechanisms of Al6061-CuO Composites

Metal matrix composites (MMCs) reinforced with Copper Oxide (CuO) and Aluminum (Al) 6061 (Al6061) alloys are being studied to determine their mechanical, physical, and dry sliding wear properties. The liquid metallurgical stir casting method with ultrasonication was employed for fabricating Al6061-CuO microparticle-reinforced composite specimens by incorporating 2–6 weight percent (wt.%) CuO particles into the matrix. Physical, mechanical, and dry sliding wear properties were investigated in Al6061-CuO MMCs, adopting ASTM standards. The experimental results show that adding CuO to an Al6061 alloy increases its density by 7.54%, hardness by 45.78%, and tensile strength by 35.02%, reducing percentage elongation by 40.03%. Dry wear measurements on a pin-on-disc apparatus show that Al6061-CuO MMCs outperform the Al6061 alloy in wear resistance. Al6061-CuO MMCs’ strength has been predicted using many strengthening mechanism models and its elastic modulus through several models. The strengthening of Al6061-CuO MMCs is predominantly influenced by thermal mismatch, more so than by Hall–Petch, Orowan strengthening, and load transfer mechanisms. As the CuO content in the composite increases, the strengthening effects due to dislocation interactions between the matrix and reinforcement particles, the coefficient of thermal expansion (CTE) difference, grain refinement, and load transfer consistently improve. The Al6061-CuO MMCs were also examined using an optical microscope (OM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and scanning electron microscopy (SEM) before and after fracture and wear tests. The investigation shows that an Al6061-CuO composite material with increased CuO reinforcement showed higher mechanical and tribological characteristics.

Anomalous Nernst Effect-Based Near-Field Imaging of Magnetic Nanostructures.

The anomalous Nernst effect (ANE) gives rise to an electrical response transverse to magnetization and an applied temperature gradient in a magnetic metal. A nanoscale temperature gradient can be generated by the use of a laser beam applied to the apex of an atomic force microscope tip, thereby allowing for spatially resolved ANE measurements beyond the optical diffraction limit. Such a method has been previously used to map in-plane magnetized magnetic textures. However, the spatial distribution of the out-of-plane temperature gradient, which is needed to fully interpret such ANE-based imaging, was not studied. We therefore use a well-known magnetic texture, a magnetic vortex core, to demonstrate the reliability of the ANE method for imaging of magnetic domains with nanoscale resolution. Moreover, since the ANE signal is directly proportional to the temperature gradient, we can also consider the inverse problem and deduce information about the nanoscale temperature distribution. Our results together with finite element modeling indicate that besides the out-of-plane temperature gradients there are even larger in-plane temperature gradients. Thus, we extend the ANE imaging to study the out-of-plane magnetization in a racetrack nanowire by detecting the ANE signal generated by in-plane temperature gradients. In all cases, a spatial resolution of ≈70 nm is obtained. These results are significant for the rapidly growing field of thermoelectric imaging of antiferromagnetic spintronic device structures.

Three-layer polarisation volume grating with enhanced diffraction efficiency and FOV in AR and VR applications

ABSTRACT In the rapidly evolving fields of Augmented Reality (AR) and Virtual Reality (VR), achieving high diffraction efficiency and a wide field of view (FOV) is critical for enhancing visual experience. This paper presents a three-layer Polarisation Volume Grating (TL-PVG) structure designed to address the limitations of single-layer PVGs in AR/VR applications. By stacking multiple PVG layers with different tilt angles, TL-PVG achieves an expanded angular bandwidth and improved diffraction efficiency, enabling brighter and more immersive displays. The proposed TL-PVG structure incorporates polarisation multiplexing to optimise the optical diffraction efficiency by approximately 75%, thereby enhancing image brightness and sharpness. The experimental results demonstrate that TL-PVG significantly outperforms traditional single-layer PVGs, offering a promising solution for waveguide elements in next-generation AR/VR displays. This study provides a comprehensive analysis of the fabrication process, optical properties, and applications of TL-PVGs, highlighting their potential to revolutionise the AR/VR technology.

Enhancing wear resistance of CoNiCrMo medium entropy alloy through cold working and aging: Tradeoffs with corrosion performance

This study investigates the wear behavior and corrosion resistance of MP35 N alloy under various conditions, including annealed, cold-worked, and aged states. The microstructure was characterized using optical microscopy, X-ray diffraction, and transmission electron microscopy. Results indicated that cold rolling induced a dislocation structure and deformation features such as mechanical twins, stacking faults, and slip bands. The presence of non-homogeneous strain and planar defects in the cold-rolled samples led to broader diffraction peaks compared to the annealed samples. The microstructure of the cold-rolled and artificially aged samples exhibited deformation features, dislocation structures, and ultra-fine precipitates. High-angle annular dark field imaging and energy-dispersive X-ray spectroscopy revealed that these precipitates were Ti-rich particles, which, along with molybdenum segregation in stacking faults, contributed to the highest hardness observed. X-ray diffraction analysis confirmed the segregation and depletion of alloying elements from the lattice during aging. Wear and corrosion tests demonstrated that while cold working and aging enhanced the wear performance of the annealed CoNiCrMo alloy, they adversely affected its corrosion resistance. Specifically, the volume loss for cold-worked and aged samples was approximately 2.7 and 2.1 times smaller than that of the annealed specimen, respectively. However, the annealed alloy exhibited a lower corrosion current density (icorr) of 70 nA cm−2 compared to the cold-worked and aged samples, which had icorr values of 130 and 200 nA cm−2, respectively.

Benchmarking luminescent properties of the arylvinylpyrimidine scaffold.

The exploration of the photophysical properties of push-pull molecules incorporating pyrimidine rings as electron-attracting moieties in their structure continues to be a fascinating area of investigation. A thorough examination of these properties not only contributes to fundamental knowledge but also provides crucial insights for the rational design of emissive materials in prospective applications. In this context, this work conducts an in-depth analysis of four families of 4,6-bis(arylvinyl)pyrimidines, evaluating the influence of substituents on both the aryl groups and position 2 of the pyrimidine ring. While previous research has primarily focused on solution studies, this work emphasizes the importance of examining solid-state photophysics. Through a multidisciplinary approach encompassing optical techniques, x-ray diffraction, and quantum chemical calculations, a comprehensive understanding of the structure-property relationships is achieved. This study underscores the intricate interplay between molecular structure, aggregation, and fluorescence behavior in pyrimidines, offering valuable insights with broader implications beyond academic realms.

Single-Extracellular-Vesicle Detection with a Plasmonic Chip and Enhanced Fluorescence Microscopy.

Endocytosis-derived extracellular vesicles (EVs), which can be as small as 100 nm, are useful for disease prediction. However, very small EVs are below the optical diffraction limit and are difficult to visualize with conventional fluorescence microscopy. In this study, single EVs captured on a plasmonic chip, where fluorescently labeled antibodies were bound over the EV surface, were detected as bright spots using plasmon-field enhanced fluorescence without any pretreatment of isolating labeled EVs, followed by analyzing the full width at half-maximum and the fluorescence peak value for each enhanced fluorescence bright spot. Bright spots smaller than the threshold determined by the observation of the fluorescent nanospheres were attributed to single EVs. The number of single EVs was quantitatively evaluated against the concentration of EV solution injected in the 1.4 pM-95 fM range. Furthermore, single EVs were detected by labeling two different membrane proteins. A molecularly imprinted polymer was applied to a capture interface on a plasmonic chip, and it is found that nonspecific adsorption of aggregates was suppressed. To accurately distinguish single EVs from aggregates of labeled antibodies, the fluorescence microscopy with transmitted light was superior to the epifluorescence method. Finally, single EVs were successfully detected with multiple targets at multiple wavelengths by using different fluorescently labeled antibodies.

Unified analytical theory of nonlinear optical diffraction by nonlinear gratings

When a pump laser shines upon a periodically poled lithium niobate (LN) thin plate nonlinear grating, second-harmonic generation (SHG) and its nonlinear diffraction occurs, with the nonlinear Raman–Nath diffraction (NRND), nonlinear Bragg diffraction (NBD), and nonlinear Cerenkov radiation (NCR) being several prominent examples. In this work we build and present a unified analytical theory to solve SHG for the NRND, NCR, and NBD processes from LN domains, domain walls, and defects. We find that the critical physical entity that governs the nonlinear diffraction is the effective nonlinear coefficient for each Fourier wave component. The analytical theory has a great generality and applicability scope. It allows us to retrieve and analyze everything about the dependence of SHG nonlinear diffraction on a series of physical and geometrical parameters such as the pump laser intensity, polarization, incidence polar and azimuthal angles, the LN thin plate thickness and its crystalline orientation, LN domain size and pitch, domain wall thickness and crystalline configuration, defect size and crystalline configuration, and the SHG diffraction beam angle and polarization. The analytical theory also enables us to analyze deeply the similarities and differences of the three nonlinear diffraction processes NRND, NCR, and NBD, build a smooth and broad connection bridge among these three processes, and construct a unified physical picture to understand, describe, and exploit these three processes of seemingly big difference. Besides, the analytical theory can be applicable to handle nonlinear diffraction by domains, domain walls, and defects in other more complicated 2D and 3D nonlinear gratings made from LN and other nonlinear crystals. Finally, the analytical theory can help to build a bridge connecting the extrinsic SHG nonlinear diffraction properties with the intrinsic domain poling and inversion material and physical properties of LN and other nonlinear crystals and explore novel nonlinear optical devices and technologies.

Real-time holographic 3D display using Split-Lohmann Fresnel computer-generated hologram (SL-FCGH).

Real-time generation of computer-generated hologram (CGH) from three-dimensional (3D) objects has been a long-standing problem in holographic display. In this paper we report a fast CGH generation algorithm, which can rapidly synthesize a 3D Fresnel hologram in only one-step backward propagation calculation in a Split-Lohmann lens-based diffraction model. In such a calculation scheme, we utilize an image padding and cropping strategy to remove image artifacts and improve the display quality in a large depth range. The generated hologram, which is called Split-Lohmann Fresnel CGH (SL-FCGH), can reproduce 3D images through free-space Fresnel diffraction optics. The computation time of the proposed method is independent of the quantized layer numbers and, therefore, can achieve real-time computation speed with a very dense depth sampling. Both simulation and experimental results of full-color holographic display prove the validation of the proposed method.

Practical limits to spatial resolution of magnetic imaging with a quantum diamond microscope

Widefield quantum diamond microscopy is a powerful technique for imaging magnetic fields with high sensitivity and spatial resolution. However, current methods to approach the ultimate spatial resolution (&amp;lt;500 nm) are impractical for routine use as they require time-consuming fabrication or transfer techniques to precisely interface the diamond sensor with the sample to be imaged. To address this challenge, we have designed a co-axial sensor holder that enables simple, repeatable sensor–sample interfacing while being compatible with high numerical aperture (NA) optics. With our new design we demonstrate low standoffs &amp;lt;500 nm with a millimeter sized sensor. We also explore the relationship between spatial resolution and NA spanning from 0.13 to 1.3. The spatial resolution shows good agreement with the optical diffraction limit at low NA but deviates at high NA, which is shown to be due to optical aberrations. Future improvements to our design are discussed, which should enable magnetic imaging with &amp;lt;500 nm resolution in an accessible, easy-to-use instrument.

Physical coherent cancellation of optical addressing crosstalk in a trapped-ion experiment

Abstract We present an experimental investigation of coherent crosstalk cancellation methods for light delivered to a linear ion chain cryogenic quantum register. The ions are individually addressed using focused laser beams oriented perpendicular to the crystal axis, which are created by imaging each output of a multi-core photonic-crystal fibre waveguide array onto a single ion. The measured nearest-neighbor native crosstalk intensity of this device for ions spaced by 5 µm is found to be ∼ 10 − 2 . We show that we can suppress this intensity crosstalk from waveguide channel coupling and optical diffraction effects by a factor &gt; 10 3 using cancellation light supplied to neighboring channels which destructively interferes with the crosstalk. We measure a rotation error per gate on the order of ϵ x ∼ 10 − 5 on spectator qubits, demonstrating a suppression of crosstalk error by a factor of &gt; 10 2 . We compare the performance to composite pulse methods for crosstalk cancellation, and describe the appropriate calibration methods and procedures to mitigate phase drifts between these different optical paths, including accounting for problems arising due to pulsing of optical modulators.

Multi-line laser 3D reconstruction method based on spatial quadric surface and geometric estimation

The traditional multi-line laser 3D reconstruction is based on binocular epipolar constraints and the equation of the laser optical plane. Firstly, matching points are identified based on the epipolar constraints. Then, the correct matching points are selected based on the optical plane equation of the multi-line laser. Finally, 3D reconstruction is performed using the selected matching points. In actual production processes involving multi-line lasers, noticeable distortion occurs due to the projection of Diffractive Optical Elements (DOE) at a large angle. This results in curved laser light planes and curved reflections on the measured objects. Under such circumstances, efficiently screening matching points using the traditional method based on the laser plane equation becomes challenging. Additionally, inherent noise in multi-line laser systems introduces errors in extracted laser center coordinates, making it impossible to directly obtain high-precision 3D data. To address these issues, this paper proposes a method that utilizes spatial quadric surfaces and geometric estimation for completing multi-line laser 3D reconstructions. By analyzing the distortion principle of DOE and the positional relationship after optical diffraction, the multi-line laser manifests as a quadric surface on the optical output plane. Consequently, by calibrating the equations of the quadric surface and applying binocular polar constraints, suitable matching points for the multi-line laser can be chosen. Once an accurate matching point is identified, a minimum geometric distance estimation can be established based on the distance constraint between the point and its corresponding epipolar line. This distance represents the separation between the left and right camera’s laser center points and their respective epipolar lines. Utilizing this estimate of the minimum geometric distance, a refined calculation can be performed to better satisfy epipolar constraints and obtain new matching points. Ultimately, utilizing these new matching points enables the completion of 3D reconstruction for multi-line lasers. In comparison with methods relying on spatial plane and epipolar constraints, our algorithm exhibits a superior degree of matchability and accuracy.According to multiple groups of test data, the average error before optimization is 0.3126 mm, and can be increased to 0.0336 mm after optimization.