A report on Wavelength

The wavelength of a sine wave, λ, can be measured between any two points with the same phase, such as between crests (on top), or troughs (on bottom), or corresponding zero crossings as shown.

Sinusoidal standing waves in a box that constrains the end points to be nodes will have an integer number of half wavelengths fitting in the box.

A standing wave (black) depicted as the sum of two propagating waves traveling in opposite directions (red and blue)

Wavelength is decreased in a medium with slower propagation.

$Refraction: upon entering a medium where its speed is lower, the wave changes direction.$

Separation of colors by a prism (click for animation)

Various local wavelengths on a crest-to-crest basis in an ocean wave approaching shore

A sinusoidal wave travelling in a nonuniform medium, with loss

A wave on a line of atoms can be interpreted according to a variety of wavelengths.

Wavelength of a periodic but non-sinusoidal waveform.

Pattern of light intensity on a screen for light passing through two slits. The labels on the right refer to the difference of the path lengths from the two slits, which are idealized here as point sources.

$Diffraction pattern of a double slit has a single-slit envelope.$

Spatial period of a periodic wave—the distance over which the wave's shape repeats.

- Wavelength

39 related topics with Alpha

Lambda

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11th letter of the Greek alphabet, representing the voiced alveolar lateral approximant.

The Greek alphabet on a black figure vessel, with a Phoenician-lamed-shaped lambda. The gamma has the shape of modern lambda.

Lambda indicates the wavelength of any wave, especially in physics, electronic engineering, and mathematics.

US Army bombers flying over near-periodic swell in shallow water, close to the Panama coast (1933). The sharp crests and very flat troughs are characteristic for cnoidal waves.

Cnoidal wave

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Nonlinear and exact periodic wave solution of the Korteweg–de Vries equation.

A cnoidal wave, characterised by sharper crests and flatter troughs than in a sine wave. For the shown case, the elliptic parameter is m = 0.9.

Crossing swells, consisting of near-cnoidal wave trains. Photo taken from Phares des Baleines (Whale Lighthouse) at the western point of Île de Ré (Isle of Rhé), France, in the Atlantic Ocean.

Validity of several theories for periodic water waves, according to Le Méhauté (1976). The light-blue area gives the range of validity of cnoidal wave theory; light-yellow for Airy wave theory; and the dashed blue lines demarcate between the required order in Stokes' wave theory. The light-gray shading gives the range extension by numerical approximations using fifth-order stream-function theory, for high waves (H > ¼ Hbreaking).

Parameter relations for cnoidal wave solutions of the Korteweg–de Vries equation. Shown is −log10 (1−m), with m the elliptic parameter of the complete elliptic integrals, as a function of dimensionless period τ √g/h and relative wave height H / h. The values along the contour lines are −log10 (1−m), so a value 1 corresponds with m = 1 − 10−1 = 0.9 and a value 40 with m = 1 − 10−40.

Undular bore and whelps near the mouth of Araguari River in north-eastern Brazil. View is oblique toward mouth from airplane at approximately 100 ft altitude.

They are used to describe surface gravity waves of fairly long wavelength, as compared to the water depth.

one nanometric carbon nanotube, photographed with scanning tunneling microscope

Nanometre

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Unit of length in the metric system, equal to one billionth (short scale) of a metre (0 m).

Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The nanometre is often used to express dimensions on an atomic scale and mostly in the molecular scale.

The nanometre is also commonly used to specify the wavelength of electromagnetic radiation near the visible part of the spectrum: visible light ranges from around 400 to 700 nm.

Wavelength of a sine wave, λ, can be measured between any two consecutive points with the same phase, such as between adjacent crests, or troughs, or adjacent zero crossings with the same direction of transit, as shown.

Wave vector

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Vector which helps describe a wave.

Its magnitude is either the wavenumber or angular wavenumber of the wave (inversely proportional to the wavelength), and its direction is ordinarily the direction of wave propagation (but not always; see below).

Spatial frequency

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Characteristic of any structure that is periodic across position in space.

Ordinary wavenumber is defined as the reciprocal of wavelength

Optical fiber

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Flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair.

Fiber crew installing a 432-count fiber cable underneath the streets of Midtown Manhattan, New York City

A TOSLINK fiber optic audio cable with red light being shone in one end transmits the light to the other end

A wall-mount cabinet containing optical fiber interconnects. The yellow cables are single mode fibers; the orange and aqua cables are multi-mode fibers: 50/125 µm OM2 and 50/125 µm OM3 fibers respectively.

Daniel Colladon first described this "light fountain" or "light pipe" in an 1842 article titled "On the reflections of a ray of light inside a parabolic liquid stream". This particular illustration comes from a later article by Colladon, in 1884.

Light reflected from optical fiber illuminates exhibited model

Use of optical fiber in a decorative lamp or nightlight

The propagation of light through a multi-mode optical fiber.

A laser bouncing down an acrylic rod, illustrating the total internal reflection of light in a multi-mode optical fiber.

Experimental attenuation curve of low loss multimode silica and ZBLAN fiber. Black triangle points and gray arrows illustrate a four order of magnitude reduction in the attenuation of silica optical fibers over four decades from ~1000 dB/km in 1965 to ~0.17 dB/km in 2005.

Theoretical loss spectra (attenuation, dB/km) for Silica optical fiber (dashed blue line) and typical ZBLAN optical fiber (solid gray line) as function of wavelength (microns).

The P4O10 cagelike structure—the basic building block for phosphate glass

Illustration of the modified chemical vapor deposition (inside) process

Cross-section of a fiber drawn from a D-shaped preform

An aerial optical fiber splice enclosure lowered during installation. The individual fibers are fused together and stored within the enclosure for protection from damage

Optical fibers can be used as sensors to measure strain, temperature, pressure, and other quantities by modifying a fiber so that the property being measured modulates the intensity, phase, polarization, wavelength, or transit time of light in the fiber.

$Airy diffraction patterns generated by light from two point sources passing through a circular aperture, such as the pupil of the eye. Points far apart (top) or meeting the Rayleigh criterion (middle) can be distinguished. Points closer than the Rayleigh criterion (bottom) are difficult to distinguish.$

Angular resolution

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Optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution.

$Log-log plot of aperture diameter vs angular resolution at the diffraction limit for various light wavelengths compared with various astronomical instruments. For example, the blue star shows that the Hubble Space Telescope is almost diffraction-limited in the visible spectrum at 0.1 arcsecs, whereas the red circle shows that the human eye should have a resolving power of 20 arcsecs in theory, though normally only 60 arcsecs.$

The Rayleigh criterion shows that the minimum angular spread that can be resolved by an image forming system is limited by diffraction to the ratio of the wavelength of the waves to the aperture width.

$The binocular microscope is a conventional optical system. Spatial resolution is confined by a diffraction limit that is a little above 200 nanometers.$

Superlens

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Lens which uses metamaterials to go beyond the diffraction limit.

$The binocular microscope is a conventional optical system. Spatial resolution is confined by a diffraction limit that is a little above 200 nanometers.$

Schematic depictions and images of commonly used metallic nanoprobes that can be used to see a sample in nanometer resolution. Notice that the tips of the three nanoprobes are 100 nanometers.

DVD (digital versatile disc). A laser is employed for data transfer.

The "Electrocomposeur" was an electron-beam lithography machine (electron microscope) designed for mask writing. It was developed in the early 1970s and deployed in the mid 1970s.

A prism composed of high performance Swiss rolls which behaves as a magnetic faceplate, transferring a magnetic field distribution faithfully from the input to the output face.

Furthermore, the level of feature detail, or image resolution, is limited to a length of a wave of radiation.

A standing wave. The red dots are the wave nodes

Node (physics)

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Point along a standing wave where the wave has minimum amplitude.

Pattern of two waves' interference (from up to down). The point represents the node.

They occur at intervals of half a wavelength (λ/2).

Plaque at the Humboldt University of Berlin: "Max Planck, who discovered the elementary quantum of action h, taught here from 1889 to 1928."

Planck constant

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First postulated by Max Planck in 1900 as part of a solution to the ultraviolet catastrophe.

Intensity of light emitted from a black body. Each curve represents behavior at different body temperatures. Planck's constant h is used to explain the shape of these curves.

The divergence of the theoretical Rayleigh–Jeans (black) curve from the observed Planck curves at different temperatures.

For example, green light with a wavelength of 555 nanometres (a wavelength that can be perceived by the human eye to be green) has a frequency of 540 THz (540 Hz).