Bernhard Michel’s Post

Optical Particle Sizing Optical particle sizing is an important application of volumetric light scattering, needed across numerous industries.  Figure (a) shows a typical measurement setup simulated in RayJack ONE®: a sample cell, which is filled with an aqueous suspension of particles, is illuminated by a convergent laser beam; concentric ring-shaped photodiodes measure the scattered light flux and are numbered with increasing diameter. The latter ranges from fractions of a mm for the inner to centimeters for the outer photodiodes. The suspension is assumed to have a bimodal particle size distribution (b). Mie theory is used for evaluation, taking into account side effects such as multiple scattering.  The resulting sensor signal is shown in (c), with the larger particles producing more signal on the inner photodiodes. Although it might look straightforward, reconstructing the particle size distribution from the sensor signals is a really difficult task, requiring advanced mathematical algorithms such as regularization.   Follow us on LinkedIn for the latest news, learn more about RayJack ONE® on our website, https://lnkd.in/dJfMUa3 and our YouTube channel: https://lnkd.in/e6U_cKFu #RayJackONE #OpticalParticleSizing #illumination #scattering #MieTheory 

Material parameters for volume scattering – part two In the previous post, we discussed the retrieval of material parameters for volume scattering. The theoretical framework for simulations is the radiative transfer equation (RTE – see more details on Wikipedia), which is a quite complicated integro-differential equation. The most commonly used approximate solution is achieved through Monte-Carlo integration, which directly leads to stochastic ray-tracing: a ray undergoes a sequence of straight propagation, deflection through scattering, or absorption (shown in the left picture). While this method is highly versatile, it tends to be slow and susceptible to statistical noise More efficient methods for solving the Radiative Transfer Equation (RTE) exist, particularly when symmetries are present. One such method is the Adding-Doubling method, which is applicable to slabs of infinite lateral extent and rotationally symmetric illumination. In this approach, the reflection and transmission matrices of thin slabs are iteratively "added" to form thicker slabs until the desired slab thickness is achieved, as illustrated in the right picture. Both Monte-Carlo method and Adding Doubling are implemented in RayJack ONE® and – except for statistical noise - yield the same results (right lower picture). Adding doubling is often orders of magnitude faster than Monte-Carlo (since it involves no ray tracing), depending on system parameters which makes it the method of choice for retrieving scattering parameters, if the symmetry conditions are met. Learn more about RayJack ONE® on our website: https://lnkd.in/dJfMUa3 and our YouTube channel: https://lnkd.in/e6U_cKFu #RayJackONE #illumination #scattering  

Happy Friday! Enjoy this micrograph of a used spark plug anode, showing corrosion, wear, and cracking on the surface. This photo was taken using a scanning electron microscope in backscatter mode, at 450x magnification. #MASTest #MaterialsScience #MaterialsTesting #Micrograph Image description: Grayscale image taken with a scanning electron microscope in backscatter mode, showing corrosion, wear, and cracking on the surface of a used spark plug anode. This image was taken at 450x magnification.

Diamond powder Grade D90 image under microscope

Nonlinear Thomson scattering: velocity asymmetry inherent in electron figure-8 motion https://lnkd.in/exqBsNvG

Diamond powder Grade D30 image under microscope

📢 𝗘𝗻𝗵𝗮𝗻𝗰𝗲𝗱 𝗦𝗶𝘇𝗲 𝗥𝗲𝘀𝗼𝗹𝘂𝘁𝗶𝗼𝗻 𝘄𝗶𝘁𝗵 𝗗𝗟𝗦 𝗙𝗹𝗼𝘄 𝗠𝗼𝗱𝗲 🎥 Unlock the next level of particle size analysis with our latest video, "Enhanced Size Resolution with DLS Flow Mode." Dive deep into how Dynamic Light Scattering (DLS) Flow Mode can revolutionize your particle characterization, providing unparalleled resolution and precision. Watch now to see how DLS Flow Mode can benefit your research and improve your analysis outcomes. #ParticleAnalysis #DLSTechnology #ResearchInnovation #SizeResolution #DynamicLightScattering #Melchers #NexusAnalyticsindonesia

HoSb offers a unique platform for exploring the interplay between extremely large magnetoresistance, magnetism and topology in an AFM matrix.

Laser linewidth and Third Harmonic Generation If a completely ideal laser with an infinitely narrow spectrum were launched into a nonlinear medium where it undergoes Third Harmonic Generation (THG), a new, infinitely narrow frequency that is three times higher would be produced. But what happens if a realistic laser with a finite linewidth undergoes THG? Does the resulting frequency-tripled line have the same width, or is it broader or more narrow? In the attached tutorial, which was inspired by a viewer question, I explain the answer to this question both intuitively and mathematically: https://lnkd.in/dSYNV6N3 The short answer is that because the frequency-tripled field in the time domain is proportional to the cube of the incident field in the time domain, the Convolution Theorem implies that the frequency-tripled spectrum is proportional to a "triple convolution" of the initial spectrum with itself. Convolving two functions always leads to a result broader than either of them, so the linewidth of a laser undergoing THG should increase! For a laser with a Gaussian line shape undergoing Second-Harmonic-Generation, one can easily show that the frequency-doubled line will be broadened by a factor of sqrt(2) compared to the initial one.

Diamond powder Grade D40 image under microscope