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Autonomous Scan Patterns for Laser Voltage Imaging
摘要： The semiconductor industry ramping up design capabilities for emerging technologies is facing new test quality and yield management challenges. To facilitate debugging of the first silicon, diagnosis of yield issues, and to enable repair processes, an accurate defect isolation is needed with support of advanced test, diagnostic, and yield analysis tools. Laser voltage imaging (LVI), laser voltage probing (LVP), and electron-beam testing are popular diagnostic techniques for scan chain failures. As scan remains instrumental in developing more advanced DFT technologies, its reliable operations are essential for test pattern bring-up, failure analysis, and yield learning. Running LVI tests at early stages of a design process involves a sophisticated infrastructure to offer a nanometer diagnostic resolution with a non-destructive failure isolation. However, as the use of external testers may not be feasible besides providing power and clock signals, the paper demonstrates how to reuse on-chip EDT compression environment to generate and apply LVI-aware scan patterns for advanced contactless test procedures. The presented approach avoids the repetitive loading of scan chains, requires no seed patterns to encode LVI tests, has virtually no area overhead, and offers a flexible selection of non-toggling scan chains in a low power test mode. Furthermore, there are no constraints or requirements imposed by designs that could limit the applicability of the scheme. The proposed solution does not compromise the test compression performance, marked by test data reduction ratios, test coverage, and test time. Hence, there are no modifications needed in existing flows and tools to implement the method besides the use of recommended polynomials.
关键词： scan cell diagnosis,logic BIST,repeated scan integrity tests,test compression,E-beam test,laser voltage imaging
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE Intelligent Transportation Systems Conference - ITSC - Auckland, New Zealand (2019.10.27-2019.10.30)] 2019 IEEE Intelligent Transportation Systems Conference (ITSC) - Graph-based Map-Aided Localization using Cadastral Maps as Virtual Laser Scans
摘要： Environment-based localization algorithms, such as laser odometry, can achieve a remarkable accuracy on the local scale. For autonomous driving, however, it is mandatory to combine these estimates with global information to overcome large scale drift. Our approach uses freely accessible cadastral plans (building footprints) together with 2D laser information and odometry in a graph-based approach to realize real-time global localization. The main contributions of our work reside in the way we create a virtual laser scan from cadastral plans, and that we consider the observation integrity by identifying corridor-like environment configurations (ambiguous positioning along the longitudinal axis). Besides, we evaluate our approach on a vehicle in two urban scenarios. We present a comparison of the obtained precision using different relevant combinations of the proposed contributions and show that we can reach an average positioning accuracy of 55cm at best without requiring a first passage of an equipped vehicle to build a map.
关键词： laser scan,autonomous driving,localization,cadastral maps,graph-based
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Thermal Analysis of New Ionic Liquids by EZ-Scan Technique
摘要： Many organic materials have been developed and studied aiming photonic aplications. Ionic liquids (IL) are organic materials in the class of molten salts and they presents many interesting physicochemical properties. IL are used in batteries, they are good stabilizers for colloidal suspensions and also green solvents for chemical reactions and processes [1]. Two new ionic liquids synthetized, BMIOMe.NTf2 and BMIOMe.N(CN)2, evidenced an alteration in the electrical conductivity when illuminated with a Xe-lamp. One hypothesis of this change of conductivity is related to the increase of carrier density. An increase of charger mobility due to thermal effects could also coperate with this modification. Besides the usual fast electronic nonlinearity, we characterize the thermal response for both IL synthetized by EZ-scan technique [2,3] in order to verify how strong is the linear absorption converted in nonradioative decay and change of sample temperature.
关键词： Ionic liquids,EZ-scan technique,thermal analysis,photonic applications
更新于2025-09-16 10:30:52
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Mg-Doped ZnO and Zn-Doped MgO Semiconductor Nanoparticles; Synthesis and Catalytic, Optical and Electro-Optical Characterization
摘要： A series of MgxZn1 – xO and ZnxMg1 – xO (mol %) were synthesized by the sol–gel method. All the synthesized nanoparticles were investigated as catalyst in the one-pot, three-component Biginelli condensation reaction of benzaldehyde, ethyl acetoacetate and urea under heterogeneous conditions. Findings revealed Mg0.007Zn0.093O (Zn7) as the best in the mentioned condensation reaction. Zn7 was characterized by FT-IR, SEM, CHN, and XRD. In addition, linear and nonlinear optical properties of MgxZn1 – xO and ZnxMg1 – xO thin films and their colloidal solutions were studied. Using an exact numerical method, some photo-physical properties of the prepared films such as dispersion curve, absorption spectrum, optical permittivity and optical band gap were attained and compared. Finally, using z-scan method at low laser irradiation, thermo-optical effect has also studied and a nonlinear refractive index due to this effect was attained. Doping effect on the optical properties was also investigated physically. It was found in both the particles groups, increasing the doping percent reduces the band gap and it suggests new optoelectronic materials with a spectrum of optical properties.
关键词： z-scan,ZnxMg1 – xO,MgxZn1 – xO,catalyst,optical band gap,nanoparticles,permittivity
更新于2025-09-16 10:30:52
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Optical and Thermal Properties of Laser-Ablated Platinum Nanoparticles Graphene Oxide Composite
摘要： Platinum nanoparticles were synthesized in graphene oxide aqueous solution using a laser ablation technique to investigate the effect of optical linear, nonlinear and thermal properties of platinum-graphene oxide nanocomposite solution. The samples were prepared with different ablation times. The platinum nanoparticles that formed a spherical shape on the surface of graphene oxide solution were authenticated using UV-visible spectrum and transmission electron microscopy patterns. The particle size decreased with increasing ablation time, and the concentration and volume fraction of samples were increased. To obtain the optical linear, nonlinear and thermal properties of platinum-graphene oxide nanocomposite solution, UV-visible spectroscopy, Z-scan, thermal lens and photoacoustic techniques were used. Consequently, the linear and nonlinear refractive indices increased with an increase in the volume fraction of platinum nanoparticles. It was observed from the spatial self-phase modulation patterns that, the optical nonlinear property of the graphene oxide was enhanced in the presence of platinum nanoparticles, and the nonlinearity increased with an increase in the volume fraction of platinum nanoparticles inside the graphene oxide solution. The thermal diffusivity and thermal effusivity of platinum nanoparticles graphene oxide were measured using a thermal lens and photoacoustic methods, respectively. The thermal diffusivity and thermal effusivity of samples were in the range of 0.0341 × 10?5 m2/s to 0.1223 × 10?5 m2/s and 0.163 W s1/2 cm?2 K?1 to 0.3192 W s1/2 cm?2 K?1, respectively. Consequently, the platinum enhanced the optical and thermal properties of graphene oxide.
关键词： graphene oxide,z-scan,spatial self-phase modulation,Pt-NPs,platinum nanoparticles/graphene oxide composite,laser ablation,photoacoustic,thermal lens
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Characterization of 8 fs Deep-UV Pulses using XPW Dispersion Scan
摘要： The measurement of few-fs-long deep-ultraviolet (DUV) pulses is one of the most demanding tasks for optical pulse characterization as these pulses are very much prone to material dispersion and space-time distortions. Therefore, the arrangements should be very carefully designed not to deteriorate the pulses in the course of the measurement. Furthermore, in this wavelength range the most popular nonlinearities used for the characterization such as second harmonic or sum frequency generation processes become unpractical or even unfeasible due to the very limited phase-matching or the even shorter wavelength of the resulted signal. Consequently, up to now most of short UV pulses were characterized by the FROG technique utilizing a degenerate four-wave mixing process, such as self diffraction [1] or transient grating formation [2]. Nevertheless, this technique suffers from rather bad signal to noise ratio and low sensitivity due to wave front splitting necessary for such method. Here we demonstrate for the first time the measurement of 8 fs DUV pulses using a dispersion scan (d-scan) apparatus. We use cross-polarized wave (XPW) generation, another degenerate four-wave mixing process without frequency conversion, as the nonlinear process [3], as we have already implemented for the characterization of few-cycle near infrared pulses [4,5]. Thanks to the single-beam geometry of d-scan no beam splitting is necessary, dramatically improving the sensitivity of the measurement and reducing the stray light. As a result we can measure DUV pulses with energy as low as 85 nJ with high fidelity. Figures 1(a) and 1(b) show the measured and retrieved d-scan traces of the UV pulses with RMS error of 2%, proving the robustness of the measurement. The retrieved pulse shape as well as the spectral intensity and the phase are displayed in Figs. 1(d) and 1(c), respectively. The generation of slightly negatively chirped 8 fs UV pulses is based on indirect pulse shaping approach [6]. Negatively chirped broadband pulses at 800 nm from a 3-m-long stretched flexible hollow fiber and a subsequent chirped mirror compressor are mixed in a 5 μm BBO crystal with narrowband pulses at 400 nm (second harmonic of the fundamental pulse). In the course of sum frequency generation the negative chirp of the broadband pulse is transferred into the UV. For the pulse characterization, the XPW signal is generated in a 50 μm thick barium fluoride crystal and the signal is filtered by a Glan-Laser polarizer. With these results we demonstrate that XPW d-scan has a great potential for the characterization of very short pulses throughout the wide transparency range of barium fluoride from the deep-UV up to the mid-IR making this technique very versatile.
关键词： pulse characterization,dispersion scan,deep-ultraviolet pulses,XPW generation
更新于2025-09-16 10:30:52
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Nonlinear Refraction of Dielectric Single Crystals under Excitation with Ultrashort Near-Infrared Laser Pulses
摘要： Nonlinear refraction in a number of crystals (KGW, KGW:Eu3+, Ba(NO3)2, BaWO4, PbMoO4, and CdWO4) that are promising for excitation of multifrequency stimulated Raman scattering is investigated by a single-beam Z-scan method. Picosecond laser pulses with a wavelength of 1064 nm generated by a YAG:Nd3+ laser were used for excitation of nonlinear optical processes. The values of n2 are compared depending on the type of the crystal, optical-axis orientation, and impurity concentration.
关键词： Z-scan method,Ultrashort near-infrared laser pulses,Dielectric single crystals,Nonlinear refraction,Stimulated Raman scattering
更新于2025-09-16 10:30:52
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Hydraulic Engineering Topographic Mapping and Modeling Based on Three Dimensional Laser Scanning Technology
摘要： Topographic mapping and modeling is one of the most basic and important work in hydraulic engineering construction. This paper present a work flow which contains data measurement, pre-process and post-process with three dimensional laser scan technology. By adopting B-tree and its expansion structure, a multi-level point cloud management and storage method has been established. Then propose a contour generation method based on scan data and the equivalent point interpolation data. A self-adaptive mesh Delaunay algorithm is introduced with point cloud data in order to generate triangular irregular network digital elevation model. Finally, the modeling accuracy and error has been analysis, the results proves this method is with high efficient and accuracy and can be provide assistance for the project construction.
关键词： topography,contour,hydraulic engineering,3D laser scan,3D model
更新于2025-09-16 10:30:52
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Evaluation of digital staining for ex vivo confocal laser scanning microscopy
摘要： Background: Ex vivo confocal laser scanning microscopy (CLSM) is a novel diagnostic tool for the fast examination of native tissue. However, CLSM produces black/white/green images, depending on the refraction indices of the tissue structures, complemented by nuclear fluorescence staining, which the vast majority of Mohs surgeons and dermatopathologists are not trained to interpret. Digital staining is applicable to ex vivo CLSM investigations to simulate the images of conventional slides stained with haematoxylin & eosin (H&E). Objectives: The aim of our study was to evaluate in detail the appearance of human skin structures using digitally stained ex vivo CLSM images and compare the results to that of conventional H&E slides of the same specimen. Methods: After providing informed consent, 26 patients donated their Burow’s triangles (healthy skin) that resulted from plastic reconstruction after the R0- excision of skin tumours. After being investigated by ex vivo CLSM, including automated digital staining (VivaScope 2500M-4G, MAVIG GmbH), the specimens were fixed in formalin, embedded in paraffin and stained with H&E. Results: Almost all skin structures in the digitally stained ex vivo CLSM images morphologically resembled the structures in the histopathological images acquired from H&E slides. Due to the high refraction index of melanin, the hair shafts appeared bright pink, and the melanocytes and melanophages were poorly imaged, resulting in a strong pink appearance that vastly differed from the appearance of conventional H&E-stained histopathology. Conclusions: Digital staining of ex vivo CLSM images is an easy and highly useful tool to facilitate the interpretation of black-field images generated by confocal laser scanning microscopy for dermatopathologists and Mohs surgeons who are familiar with H&E staining. Unlike the pigmented structures, the cutaneous and subcutaneous structures had excellent visualization with only minimal differences from their appearance on H&E slides.
关键词： digital staining,ex vivo confocal laser scan microscopy,dermatopathology
更新于2025-09-16 10:30:52
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Wavelength and pump-power dependent nonlinear refraction and absorption in a semiconductor disk laser
摘要： We characterize both nonlinear refraction and absorption in a vertical-external-cavity surface-emitting laser (VECSEL) as a function of pump irradiance over the whole range of lasing wavelengths. We observe an approximately linear decrease in magnitude for both nonlinear refraction and nonlinear absorption with optical pumping when the thermally induced shift of the lasing wavelength is considered. Our results are of particular significance for understanding self-modelocking of VECSELs which might be driven by nonlinear lensing.
关键词： mode-locked semiconductor lasers,Z-scan,Nonlinear refractive index,VECSELs
更新于2025-09-16 10:30:52