What ispolarization ofwaves in Physics

Light sources from lamps to stars typically give off light waves that wiggle at a range of different angles. This jumble of waves is known as unpolarized light. Polarized light, on the other hand, is unjumbled: its waves all wiggle the same way, at the same angle. (For help picturing this, check out the artist’s depictions at 1:30 in this PBS video.)

Maria Temming is the Assistant Managing Editor at Science News Explores. She has bachelor's degrees in physics and English, and a master's in science writing.

Sunlight reflecting off water, for instance, can become polarized. The incoming light waves from the sun wiggle all different ways. But the light waves that bounce off the surface of the water are all mostly wiggling at the same angle. Pavement is another surface that can polarize reflected light.

Light can become polarized when reflecting off flat surfaces like puddles and pavement. Polarized sunglasses can then specifically block out those polarized light waves, reducing the glare that reaches a driver’s eyes.

We believe that our inverse-designed flat MDLs, which can be manufactured using low-cost imprinting techniques, could prove widely applicable—especially where weight and restricted form factor are important considerations, as in aerospace and airborne imaging as well as augmented and virtual reality displays.

Polarizationdefinition in Chemistry

glare: Also called direct glare, it is light that travels directly from a light source and into someone’s eyes. It reduces the ability to see at night. Direct glare is one of three types of light pollution.

Without tools like sunglasses, humans typically can’t detect the polarization of light. But other animals can. Examples include mantis shrimp, fiddler craps and some beetles, birds and fish.

Top left: Multi-level diffractive lenses (MDLs) can achieve extreme depth of focus, large operating bandwidths and high numerical apertures. Top right: Scanning electron micrograph of an exemplary MDL. Middle row: Experimental demonstration of extreme depth of focus (left) and MTF of high-NA MDL (right). Bottom row: Photograph of MDL images in the visible (strehl ratio = 0.8), near-infrared (NIR) and longwave infrared (LWIR) bands. Rightmost panel shows composite visible-NIR-LWIR image with a single MDL and multiple sensors. [Enlarge figure]

Using this concept, we have shown that allowing the phase in the image plane of a flat lens to be a free parameter enables imaging properties of unprecedented versatility in flat, multilevel diffractive lenses (MDLs) through careful design of different diffractive surfaces.1 The properties we have shown in such flat lenses include super-achromaticity,2,3 extreme depth-of-focus (EDOF)4 and high numerical aperture.5 In each case, the design principle and method remain the same, the only change being in the formulation of the figure of merit of the design optimization for the desired MDL property. These flat lenses can be easily fabricated using one-step grayscale lithography.

mantis shrimp: A marine animal related to crabs and lobsters. Mantis shrimp use armlike body parts to kill prey. They are often multicolored and have a very complex vision system.

Polarisationmeaningin Physics

molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

Apratim Majumder, Monjurul Meem, Sourangsu Banerji and Berardi Sensale-Rodriguez, University of Utah, Salt Lake City, UT, USA

Another way to polarize light is to pass it through a filter. Such filters are made up of molecules that are all aligned the same way. This allows only light waves wiggling at specific angles to pass through. For example, some sunglasses contain polarizing filters. These glasses help reduce the amount of reflected light — or glare — that reaches a wearer’s eyes. That can block out glare from roadways or puddles to help protect drivers’ eyes and allow them to see more clearly.

Polarizationby reflection

Polarization of lightnotes PDF

Light can also become polarized as it passes from one type of material into another. This is a process called refraction. And light can become polarized when it bounces, or scatters off atoms as it passes through a substance. This happens to moonlight and sunlight that travels through Earth’s atmosphere.

Light can become polarized when it bounces off of a surface. The amount that it is polarized depends on the angle at which the light hits the surface. It also depends on what the surface is made of.

We have demonstrated an MDL that achieves an extreme depth of focus by more than four orders of magnitude.4 Using this flat lens, we were able to maintain focus for objects that are separated by as large a distance as roughly 6 m in our experiments. When illuminated by collimated light at λ = 0.85 µm, the MDL produced a beam that remained in focus from 5 mm to 1200 mm. We have also demonstrated super-achromatic MDLs operating in the LWIR (8–12 μm), visible to NIR (0.45–1 μm), visible to LWIR (0.45–15 µm) and even the far IR (1.5–150 μm). Finally, we successfully demonstrated an MDL with thickness less than 1.35 µm, a diameter of 4.13 mm and NA = 0.9 at an operating wavelength of 850 nm (bandwidth approximately 35 nm).5

Plane polarizedlight

Polarized and unpolarizedlight

beetle: An order of insects known as Coleoptera, containing at least 350,000 different species. Adults tend to have hard and/or horn-like “forewings” which covers the wings used for flight.

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A lens is the most fundamental and essential element in any imaging system. However, traditional refractive lenses are bulky owing to their curvature. Flat diffractive lenses can overcome this difficulty, but traditional diffractive optics have limited reach, primarily due to chromaticity.

filter: (n.) Something that allows some materials to pass through but not others, based on their size or some other feature. (v.) The process of screening some things out on the basis of traits such as size, density, electric charge. (in physics) A screen, plate or layer of a substance that absorbs light or other radiation or selectively prevents the transmission of some of its components.

refraction: The change in direction of light (or any other wave) as it passes through some material. For example, the path of light leaving water and entering air will bend, making partially submerged objects to appear to bend at the water’s surface.

Light is made up of waves. They wiggle as they zip through space. They can wiggle up and down, left and right, and any angle in between. Light is polarized when its waves all wiggle at the same angle.

Meaning of polarization of lightin physics

angle: The space (usually measured in degrees) between two intersecting lines or surfaces at or close to the point where they meet.

Recently, we have shown that by treating the “imaging” phenomenon as simply information transfer from the object to the image plane, the spatial distribution of the phase in the focal plane can be an arbitrary function. (Here we refer to the phase of a scalar electromagnetic field, but the argument is equally valid for vector fields.) This is true because, in the vast majority of imaging applications, only the intensity, as recorded by the image sensor, is of primary interest for producing an image.

polarization: (in physics) The condition — or creation of a condition — in which rays of wavelengths of light exhibit different properties when viewed from different directions.