Chasing Waves: The Story of John Scott Russell and the KdV Equation

Brianne Costa May 9, 2018

During his life, John Scott Russell chased his passion for science — literally. While watching horses pull a boat through a shallow canal, he noticed a wave behaving strangely and followed it for one or two miles on horseback. For the rest of his life, he continued to chase this wave (which he called the “wave of translation”) figuratively, persevering even when his theories were ridiculed by scientists. Did Scott Russell ever catch up to his wave?

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Uttam Pal April 6, 2018

In 1875, John Kerr placed current-carrying coils in holes on either side of a glass slab, which created an electric field. After a polarized beam of light passed through the slab, he noticed that the polarization was different. This difference is related to the change in the glass’ refractive index, which is proportional to the square of the electric field — a phenomenon called the Kerr effect. See how to model this effect and other linear and nonlinear phenomena.

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Yosuke Mizuyama January 8, 2018

In the wave optics field, it is difficult to simulate large optical systems in a way that rigorously solves Maxwell’s equation. This is because the waves that appear in the system need to be resolved by a sufficiently fine mesh. The beam envelopes method in the COMSOL Multiphysics® software is one option for this purpose. In this blog post, we discuss how to use the Electromagnetic Waves, Beam Envelopes interface and handle its restrictions.

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Uttam Pal December 4, 2017

On a bright evening in 1669, Professor Erasmus Bartholinus looked through a piece of an Icelandic calcite crystal he had placed onto a bench. He observed when he covered text on the bench with the stone, it appeared as a double image. The observed optical phenomenon, called birefringence, involves a beam of light that splits into two parallel beams while emerging out of a crystal. Here, we demonstrate a modeling approach for this effect.

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Uttam Pal September 19, 2017

In 1870, an audience watched as a stage was set with two buckets, one on top of the other. Due to a small hole in the upper bucket, water poured into the lower bucket, bending as it did so. To the audience’s amazement, sunlight followed the bend of water — a phenomenon later termed total internal reflection. The performer on stage, John Tyndall, was one of the many scientists who tried to control the most visible form of energy: light.

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Walter Frei June 6, 2017

Whenever light is incident on a dielectric material, like glass, part of the light is transmitted while another part is reflected. Sometimes, we add a metal coating, such as gold, which alters the transmittance and reflectance as well as leads to some absorption of light. The dielectric surface and the metal coating also often have some random variations in height and thickness. In this blog post, we will introduce and develop a computational model for this situation.

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Bridget Cunningham April 17, 2017

Optical fibers that deliver midinfrared wavelengths are in high demand for a range of relative applications. As infrared transparent materials, semiconductors are useful for this purpose when combined with silica, helping to realize a new generation of midinfrared fiber optics. While important to performance, measuring the optical losses of such structures can be challenging experimentally because of time and costs. Simulation enables us to efficiently model this behavior for varying wavelengths and fiber geometries and identify strategies to reduce losses.

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Yosuke Mizuyama February 27, 2017

We previously learned how to calculate the Fourier transform of a rectangular aperture in a Fraunhofer diffraction model in the COMSOL Multiphysics® software. In that example, the aperture was given as an analytical function. The procedure is a bit different if the source data for the Fourier transformation is a computed solution. In this blog post, we will learn how to implement the Fourier transformation for computed solutions with an electromagnetic simulation of a Fresnel lens.

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Caty Fairclough February 17, 2017

While electro-optic (EO) routers are currently used in on-chip optical communication systems, they may require too much power for some applications. In these situations, we can look to monolithically integrated magneto-optic (MO) routers as low-power alternatives. Designing these routers can be challenging. With multiphysics simulation, we can analyze on-chip MO routers and the manufacturing techniques used to create them.

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Andrew Strikwerda January 30, 2017

Welcome back to our discussion on multiscale modeling in high-frequency electromagnetics. Multiscale modeling is a simulation challenge that arises when there are vastly different scales in a single simulation, such as the size of an antenna compared to the distance between the antenna and its target. Today, in Part 4 of the series, we will examine how we can construct a multiscale model by coupling a Full-Wave antenna simulation with a geometrical optics simulation using the Ray Optics Module.

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Andrew Strikwerda January 18, 2017

In Part 3 of our series on multiscale modeling in high-frequency electromagnetics, let’s turn our attention to the receiving antenna. We’ve already covered theory and definitions in Part 1 and radiating antennas in Part 2. Today, we will couple a radiating antenna at one location with a receiving antenna 1000 λ away. For verification, we will calculate the received power via line-of-sight transmission and compare it with the Friis transmission line equation that we covered in Part 1.

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