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c_r1fjqkj8vsxt | They have to use it either with both eyes open and one eye looking into the collimator sight, with one eye open and moving the head to alternately see the sight and the target, or with one eye to partially see the sight and target at the same time. Adding a beam splitter allows the viewer to see the reticle and the fie... | Collimator |
c_3l9d6u9x505d | In optics, a conjugate plane or conjugate focal plane of a given plane P, is the plane P′ such that points on P are imaged on P′. If an object is moved to the point occupied by its image, then the moved object's new image will appear at the point where the object originated. In other words, the object and its image are... | Conjugate focal plane |
c_992k8zmu82ik | Depending on how an optical system is designed, there can be multiple planes that are conjugate to a specific plane (e.g. intermediate and final image planes for an object plane). The points that span conjugate planes are called conjugate points.For a thin lens or a curved mirror, where u is the distance from the objec... | Conjugate focal plane |
c_t6d6fk4xmjxo | In a telescope, the subject focal plane (eg. the location of a star) is at infinity and the conjugate image plane, at which the image sensor is placed, is said to be an infinite conjugate. In microscopy and macro photography, the subject is close to the lens, so the plane at which the image sensor is placed is said to ... | Conjugate focal plane |
c_l7x3jdjuw8dx | In optics, a diaphragm is a thin opaque structure with an opening (aperture) at its center. The role of the diaphragm is to stop the passage of light, except for the light passing through the aperture. Thus it is also called a stop (an aperture stop, if it limits the brightness of light reaching the focal plane, or a f... | Iris diaphragm |
c_hq4hy1m7nuzr | The centre of the diaphragm's aperture coincides with the optical axis of the lens system. Most modern cameras use a type of adjustable diaphragm known as an iris diaphragm, and often referred to simply as an iris. See the articles on aperture and f-number for the photographic effect and system of quantification of var... | Iris diaphragm |
c_gawalbj6moe7 | In optics, a dichroic material is either one which causes visible light to be split up into distinct beams of different wavelengths (colours) (not to be confused with dispersion), or one in which light rays having different polarizations are absorbed by different amounts. | Dichroic dye |
c_gcwuvsvrcdo7 | In optics, a diffraction grating is an optical grating with a periodic structure that diffracts light into several beams travelling in different directions (i.e., different diffraction angles). The emerging coloration is a form of structural coloration. The directions or diffraction angles of these beams depend on the ... | Grating equation |
c_h5o3xlf5ebj1 | Because of this, diffraction gratings are commonly used in monochromators and spectrometers, but other applications are also possible such as optical encoders for high precision motion control and wavefront measurement.For typical applications, a reflective grating has ridges or rulings on its surface while a transmiss... | Grating equation |
c_8dlktbfqplej | The first man-made diffraction grating was made around 1785 by Philadelphia inventor David Rittenhouse, who strung hairs between two finely threaded screws. This was similar to notable German physicist Joseph von Fraunhofer's wire diffraction grating in 1821. The principles of diffraction were discovered by Thomas Youn... | Grating equation |
c_qptsxp2nd7f7 | Using these principles, Fraunhofer was the first who used a diffraction grating to obtain line spectra and the first who measured the wavelengths of spectral lines with a diffraction grating. Gratings with the lowest line-distance (d) were created, in the 1860s, by Friedrich Adolph Nobert (1806–1881) in Greifswald; the... | Grating equation |
c_tmq7eq47bnsx | A usual diffraction grating has parallel lines (It is true for 1-dimensional gratings, but 2 or 3-dimensional gratings are also possible and they have their own applications such as wavefront measurement), while a CD has a spiral of finely spaced data tracks. Diffraction colors also appear when one looks at a bright po... | Grating equation |
c_pam699ed0s7g | In optics, a diffuser (also called a light diffuser or optical diffuser) is any material that diffuses or scatters light in some manner to transmit soft light. Diffused light can be easily obtained by reflecting light from a white surface, while more compact diffusers may use translucent material, including ground glas... | Diffusion filter |
c_4gcg9iv29wz0 | In optics, a dispersive prism is an optical prism that is used to disperse light, that is, to separate light into its spectral components (the colors of the rainbow). Different wavelengths (colors) of light will be deflected by the prism at different angles. This is a result of the prism material's index of refraction ... | Dispersive prism |
c_g46xjguyhmm6 | The dispersion of white light into colors by a prism led Sir Isaac Newton to conclude that white light consisted of a mixture of different colors. Triangular prisms are the most common type of dispersive prism. Other types of dispersive prism exist that have more than two optical interfaces; some of them combine refrac... | Dispersive prism |
c_vbs7r9l1ea6z | In optics, a doublet is a type of lens made up of two simple lenses paired together. Such an arrangement allows more optical surfaces, thicknesses, and formulations, especially as the space between lenses may be considered an "element". With additional degrees of freedom, optical designers have more latitude to correct... | Doublet (lens) |
c_4ws7f5dvhzag | In optics, a frequency comb is a laser source whose spectrum consists of a series of discrete, equally spaced frequency lines. Frequency combs can be generated by a number of mechanisms, including periodic modulation (in amplitude and/or phase) of a continuous-wave laser, four-wave mixing in nonlinear media, or stabili... | Frequency comb |
c_8fzrls5lb8wx | In optics, a nematicon is a spatial soliton in nematic liquid crystals (NLC). The name was invented in 2003 by G. Assanto. and used thereafter Nematicons are generated by a special type of optical nonlinearity present in NLC: the light induced reorientation of the molecular director (i.e. the average molecular orientat... | Nematicon |
c_3ldmc9fvwdr5 | Nematicons are easy to generate (with mW optical power or less ) because the NLC dielectric medium exhibits the following properties: A very large nonlinear response: the effective nonlinearity is typically eight orders of magnitude larger than that of carbon disulfide. This means that much lower optical powers are nec... | Nematicon |
c_oxkd6zi2rhe0 | A nonlocal response: the nonlinear response is not limited to the location of the optical field. Instead the response profile is wider than the light beam. A high nonlocality allows for stable soliton propagation even in the case of two transverse dimensions. | Nematicon |
c_b15k4js5jd1r | Higher or lower powers than the exact value required for a soliton to exist lead to breathing solitons.A saturable all-optical response: the director of the liquid crystal tends to align along the electric field of the light beam. For powerful beams the molecular director becomes parallel to the field and no further re... | Nematicon |
c_j92ztc0o0vjd | In optics, a pencil or pencil of rays is a geometric construct used to describe a beam or portion of a beam of electromagnetic radiation or charged particles, typically in the form of a narrow beam (conical or cylindrical). Antennas which strongly bundle in azimuth and elevation are often described as "pencil-beam" ant... | Pencil beam |
c_9ot2xeqprfdr | Such antennas are used for tracking radar, and the process is known as beamforming. In optics, the focusing action of a lens is often described in terms of pencils of rays. In addition to conical and cylindrical pencils, optics deals with astigmatic pencils as well.In electron optics, scanning electron microscopes use ... | Pencil beam |
c_nxo6x1ryk146 | In optics, a perfect mirror is a mirror that reflects light (and electromagnetic radiation in general) perfectly, and does not transmit or absorb it. | Perfect mirror |
c_wp49p4ip2ily | In optics, a ray is an idealized geometrical model of light or other electromagnetic radiation, obtained by choosing a curve that is perpendicular to the wavefronts of the actual light, and that points in the direction of energy flow. Rays are used to model the propagation of light through an optical system, by dividin... | Light rays |
c_5gs0ddmcybpt | Ray tracing uses approximate solutions to Maxwell's equations that are valid as long as the light waves propagate through and around objects whose dimensions are much greater than the light's wavelength. Ray optics or geometrical optics does not describe phenomena such as diffraction, which require wave optics theory. ... | Light rays |
c_meuakw56g8i5 | In optics, a relay lens is a lens or a group of lenses that receives the image from the objective lens and relays it to the eyepiece. Relay lenses are found in refracting telescopes, endoscopes, and periscopes to optically manipulate the light path, extend the length of the whole optical system, and usually serve the p... | Relay lens |
c_zgf5s9eoz46z | For example, in a SLR camera the zoom lens produces an image plane where the image sensor or photographic film would usually go. If you place another lens with focal length f at the distance 2f from that image plane and then put an image sensor at 2f beyond that lens, that lens will relay the first image to the second ... | Relay lens |
c_j8keyqbahaoa | If a longer distance is needed, this can be repeated. In practice, the lens will be an achromatic doublet. In modern optical telescopes and telescopic sights with a dual-focal plane design, the objective image is typically already inverted upon reaching the relay lenses, and thus needed to be inverted again back into a... | Relay lens |
c_b82uxvar6woj | The relay lens group is the optical component responsible for that re-inversion, and therefore sometimes collectively called the erector lenses. Also, for endoscope applications, where small tube diameter is desirable, most of the tube is filled with glass, with thin air gaps to allow for powered surfaces; because marg... | Relay lens |
c_padp921ighfv | In optics, a simple lens or singlet lens is a lens consisting of a single simple element. Typical examples include a magnifying glass or a lens in a pair of simple reading glasses.Simple lenses are prone to aberrations, especially chromatic aberration. They cannot be used for precise imaging and make poor camera lenses... | Singlet lens |
c_hr8eecg3f8gz | They are commonly used for laser applications, however, where the beams are both monochromatic (minimizing chromatic aberration) and narrow (minimizing spherical aberration). Some cameras with fixed lenses have been made using a simple lens, usually a meniscus lens with the convex face facing outward. In such examples ... | Singlet lens |
c_kg9pp4r9wmhi | In optics, a supercontinuum is formed when a collection of nonlinear processes act together upon a pump beam in order to cause severe spectral broadening of the original pump beam, for example using a microstructured optical fiber. The result is a smooth spectral continuum (see figure 1 for a typical example). There is... | Supercontinuum |
c_isi8pdlzzl0e | In addition the term supercontinuum itself did not gain widespread acceptance until this century, with many authors using alternative phrases to describe their continua during the 1970s, 1980s and 1990s. During the last decade, the development of supercontinua sources has emerged as a research field. This is largely du... | Supercontinuum |
c_owjj0c7fhmag | This renewed research has created a variety of new light sources which are finding applications in a diverse range of fields, including optical coherence tomography, frequency metrology, fluorescence lifetime imaging, optical communications, gas sensing and many others. The application of these sources has created a fe... | Supercontinuum |
c_4zny0073qxnr | In optics, a thin film is a layer of material with thickness in the sub-nanometer to micron range. As light strikes the surface of a film, it is either transmitted or reflected at the upper surface. Light that is transmitted reaches the bottom surface and may once again be transmitted or reflected. The Fresnel equation... | Thin-film diffraction |
c_huxz5s2dioux | The light reflected from the upper and lower surfaces will interfere. The degree of constructive or destructive interference between the two light waves depends on the difference in their phase. This difference in turn depends on the thickness of the film layer, the refractive index of the film, and the angle of incide... | Thin-film diffraction |
c_1lw8ozcekvs3 | Additionally, a phase shift of 180° or π {\displaystyle \pi } radians may be introduced upon reflection at a boundary depending on the refractive indices of the materials on either side of the boundary. This phase shift occurs if the refractive index of the medium the light is travelling through is less than the refrac... | Thin-film diffraction |
c_qb7xk0ncwaga | In optics, a thin lens is a lens with a thickness (distance along the optical axis between the two surfaces of the lens) that is negligible compared to the radii of curvature of the lens surfaces. Lenses whose thickness is not negligible are sometimes called thick lenses. The thin lens approximation ignores optical eff... | Thin lens |
c_pdw5q09l3nip | In optics, a tophat (or top-hat) beam such as a laser beam or electron beam has a near-uniform fluence (energy density) within a circular disk. It is typically formed by diffractive optical elements from a Gaussian beam. Tophat beams are often used in industry, for example for laser drilling of holes in printed circuit... | Tophat beam |
c_bpdax46h8uru | In optics, a window is an optical element that is transparent to a range of wavelengths, and that has no optical power. Windows may be flat or curved. They are used to block the flow of air or other fluids while allowing light to pass into or out of an optical system. | Window (optics) |
c_0khzufjtslgw | In optics, aberration is a property of optical systems, such as lenses, that causes light to be spread out over some region of space rather than focused to a point. Aberrations cause the image formed by a lens to be blurred or distorted, with the nature of the distortion depending on the type of aberration. Aberration ... | Aberration in optical systems |
c_7kk975d3b2xp | Aberrations occur because the simple paraxial theory is not a completely accurate model of the effect of an optical system on light, rather than due to flaws in the optical elements.An image-forming optical system with aberration will produce an image which is not sharp. Makers of optical instruments need to correct op... | Aberration in optical systems |
c_eufm6y4553nv | In optics, absorbance or decadic absorbance is the common logarithm of the ratio of incident to transmitted radiant power through a material, and spectral absorbance or spectral decadic absorbance is the common logarithm of the ratio of incident to transmitted spectral radiant power through a material. Absorbance is di... | Absorbance |
c_5trhcz60rhqz | In optics, an ARROW (anti-resonant reflecting optical waveguide) is a type of waveguide that uses the principle of thin-film interference to guide light with low loss. It is formed from an anti-resonant Fabry–Pérot reflector. The optical mode is leaky, but relatively low-loss propagation can be achieved by making the F... | ARROW waveguide |
c_hibzuwyt6utv | In optics, an Abbe prism, named for its inventor, the German physicist Ernst Abbe, is a type of constant deviation dispersive prism similar to a Pellin–Broca prism. | Abbe prism |
c_waqap1m1haof | In optics, an afocal system (a system without focus) is an optical system that produces no net convergence or divergence of the beam, i.e., has an infinite effective focal length. This type of system can be created with a pair of optical elements where the physical distance d between the elements is equal to the sum of... | Afocal system |
c_twvkytwk0aeu | In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of the bundle of rays that come to a focus in the image plane. An optical system typically has many openings or structures that limit the ray bundles... | Aperture |
c_8wl5qfv555an | In general, these structures are called stops, and the aperture stop is the stop that primarily determines the ray cone angle and brightness at the image point. In some contexts, especially in photography and astronomy, aperture refers to the diameter of the aperture stop rather than the physical stop or the opening it... | Aperture |
c_se8fruqmade1 | One then speaks of a telescope as having, for example, a 100-centimeter aperture. The aperture stop is not necessarily the smallest stop in the system. Magnification and demagnification by lenses and other elements can cause a relatively large stop to be the aperture stop for the system. | Aperture |
c_oefbcoqs31u0 | In astrophotography, the aperture may be given as a linear measure (for example in inches or mm) or as the dimensionless ratio between that measure and the focal length. In other photography, it is usually given as a ratio. Sometimes stops and diaphragms are called apertures, even when they are not the aperture stop of... | Aperture |
c_5dyasysk80q3 | The word aperture is also used in other contexts to indicate a system which blocks off light outside a certain region. In astronomy, for example, a photometric aperture around a star usually corresponds to a circular window around the image of a star within which the light intensity is assumed. The word "aperture" is a... | Aperture |
c_65t2lz3c7bnv | For example, in military terms, a bunker's aperture means a small peeking hole made artificially or by natural means. A bunker's aperture can be used for preserving the body from enemy fire while achieving a clear line of sight. (Infantry Combat/The Rifle Platoon/John F. Antal p.91) | Aperture |
c_8dtp3bmigdse | In optics, an erect image is one that appears right-side up. An image is formed when rays from a point on the original object meet again after passing through an optical system. In an erect image, directions are the same as those in the object, in contrast to an inverted image. | Erect image |
c_4i43185h6xrq | It is one of the properties of images formed in a plane mirror. Some telescopes and other devices such as the camera obscura present an inverted image on the viewing surface. Mirrors and compound prism elements can be used to achieve an erect image instead. | Erect image |
c_tlfwuxn9p5nl | In optics, an image-forming optical system is a system capable of being used for imaging. The diameter of the aperture of the main objective is a common criterion for comparison among optical systems, such as large telescopes. The two traditional optical systems are mirror-systems (catoptrics) and lens-systems (dioptri... | Image-forming device |
c_17h13h1rllfy | Catoptrics and dioptrics have a focal point that concentrates light onto a specific point, while optical fiber the transfer of an image from one plane to another without the need for an optical focus. Isaac Newton is reported to have designed what he called a catadioptrical phantasmagoria, which can be interpreted to m... | Image-forming device |
c_ed2uyjm3cmsw | Newton believed that such correction was impossible, because he thought the path of the light depended only on its color. In 1757 John Dollond was able to create an achromatised dioptric, which was the forerunner of the lenses used in all popular photographic equipment today. | Image-forming device |
c_czw77a008x8e | Lower-energy X-Rays are the highest energy electromagnetic radiation that can be formed into an image, using a Wolter telescope. There are three types of Wolter telescopes Near infrared is typically the longest wavelength that are handled optically, such as in some large telescopes. == References == | Image-forming device |
c_x7gham8zghnj | In optics, an index-matching material is a substance, usually a liquid, cement (adhesive), or gel, which has an index of refraction that closely approximates that of another object (such as a lens, material, fiber-optic, etc.). When two substances with the same index are in contact, light passes from one to the other w... | Index-matching gel |
c_y0698ahwxeyi | In optics, an isotropic radiator is a point source of light. The Sun approximates an (incoherent) isotropic radiator of light. Certain munitions such as flares and chaff have isotropic radiator properties. Whether a radiator is isotropic is independent of whether it obeys Lambert's law. As radiators, a spherical black ... | Isotropic antenna |
c_95l3ke5e23ut | In optics, an optical medium is material through which light and other electromagnetic waves propagate. It is a form of transmission medium. The permittivity and permeability of the medium define how electromagnetic waves propagate in it. | Optical medium |
c_jgkeowxpghub | In optics, an ultrashort pulse, also known as an ultrafast event, is an electromagnetic pulse whose time duration is of the order of a picosecond (10−12 second) or less. Such pulses have a broadband optical spectrum, and can be created by mode-locked oscillators. Amplification of ultrashort pulses almost always require... | Femtosecond pulse |
c_7et2tdad6uim | These processes are studied in the field of nonlinear optics. In the specialized literature, "ultrashort" refers to the femtosecond (fs) and picosecond (ps) range, although such pulses no longer hold the record for the shortest pulses artificially generated. Indeed, x-ray pulses with durations on the attosecond time sc... | Femtosecond pulse |
c_5fu7k05os7q1 | In optics, any optical instrument or system – a microscope, telescope, or camera – has a principal limit to its resolution due to the physics of diffraction. An optical instrument is said to be diffraction-limited if it has reached this limit of resolution performance. Other factors may affect an optical system's perfo... | Diffraction limit |
c_hu0bezk7ul5f | As one decreases the size of the aperture of a telescopic lens, diffraction proportionately increases. At small apertures, such as f/22, most modern lenses are limited only by diffraction and not by aberrations or other imperfections in the construction. For microscopic instruments, the diffraction-limited spatial reso... | Diffraction limit |
c_xlcm76jwpuun | In astronomy, a diffraction-limited observation is one that achieves the resolution of a theoretically ideal objective in the size of instrument used. However, most observations from Earth are seeing-limited due to atmospheric effects. Optical telescopes on the Earth work at a much lower resolution than the diffraction... | Diffraction limit |
c_13jq73t362mc | Advanced observatories have started using adaptive optics technology, resulting in greater image resolution for faint targets, but it is still difficult to reach the diffraction limit using adaptive optics. Radio telescopes are frequently diffraction-limited, because the wavelengths they use (from millimeters to meters... | Diffraction limit |
c_k8gd3lm9lm6p | In optics, chromatic aberration (CA), also called chromatic distortion and spherochromatism, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light. The refractive index of most transparent materials decreas... | Lateral chromatic aberration |
c_38fbk1wu4nr7 | In optics, corner reflectors typically consist of three mirrors or reflective prism faces which return an incident light beam in the opposite direction. In surveying, retroreflector prisms are commonly used as targets for long-range electronic distance measurement using a total station. Five arrays of optical corner re... | Radar reflector |
c_s071o625lacy | The three largest were placed by NASA as part of the Apollo program, and the Soviet Union built two smaller ones into the Lunokhod rovers. Automobile and bicycle tail lights are molded with arrays of small corner reflectors, with different sections oriented for viewing from different angles. Reflective paint for visibi... | Radar reflector |
c_e2nx7zlue3iv | In optics, defocus is the aberration in which an image is simply out of focus. This aberration is familiar to anyone who has used a camera, videocamera, microscope, telescope, or binoculars. Optically, defocus refers to a translation of the focus along the optical axis away from the detection surface. | Defocus aberration |
c_5whhkc0wwbtw | In general, defocus reduces the sharpness and contrast of the image. What should be sharp, high-contrast edges in a scene become gradual transitions. Fine detail in the scene is blurred or even becomes invisible. Nearly all image-forming optical devices incorporate some form of focus adjustment to minimize defocus and ... | Defocus aberration |
c_la9epbj1liny | In optics, differential group delay is the difference in propagation time between the two eigenmodes X and Y polarizations. Consider two eigenmodes that are the 0° and 90° linear polarization states. If the state of polarization of the input signal is the linear state at 45° between the two eigenmodes, the input signal... | Differential group delay |
c_nwxwqm7szfms | In optics, femtosecond pulse shaping refers to manipulations with temporal profile of an ultrashort laser pulse. Pulse shaping can be used to shorten/elongate the duration of optical pulse, or to generate complex pulses. | Femtosecond pulse shaping |
c_24ouhcqolu1j | In optics, image/optical distortion is a divergence from rectilinear projection caused by a change in magnification with increasing distance from the optical axis of an optical system. | Audio Distortion |
c_vknsksw9sxpv | In optics, modulation transfer function indicates the capability of optical contrast transmission. For example, when observing a series of black-white-light fringes drawn with a specific spatial frequency, the image quality may decay. White fringes fade while black ones turn brighter. The modulation transfer function i... | Transfer characteristic |
c_onax8yznxnu0 | In optics, octagonal prisms are used to generate flicker-free images in movie projectors. | Octagonal prism |
c_tiqx92f6yrzc | In optics, optical bistability is an attribute of certain optical devices where two resonant transmissions states are possible and stable, dependent on the input. Optical devices with a feedback mechanism, e.g. a laser, provide two methods of achieving bistability. Absorptive bistability utilizes an absorber to block l... | Optical bistability |
c_4hiym509qoug | The second state resides at the point where the light intensity overcomes the absorber's ability to block light. Refractive bistability utilizes an optical mechanism that changes its refractive index inversely dependent on the intensity of the source light. The first bistable state resides at a given intensity where no... | Optical bistability |
c_hxyaths82lfc | In optics, optical path length (OPL, denoted Λ in equations), also known as optical length or optical distance, is the length that light needs to travel through a vacuum to create the same phase difference as it would have when traveling through air. It is calculated by taking the product of the geometric length of the... | Optical path difference |
c_wx7wghwm0kpl | In optics, optical path length (OPL, denoted Λ in equations), also known as optical length or optical distance, is the length that light needs to travel through air to create the same phase difference as it would have when traveling through some homogeneous medium. It is calculated by taking the product of the geometri... | Optical length |
c_yqdti0ts3vt1 | In optics, optical power (also referred to as dioptric power, refractive power, focusing power, or convergence power) is the degree to which a lens, mirror, or other optical system converges or diverges light. It is equal to the reciprocal of the focal length of the device: P = 1/f. High optical power corresponds to sh... | Lens power |
c_hwsd6sd2nj9m | Converging lenses have positive optical power, while diverging lenses have negative power. When a lens is immersed in a refractive medium, its optical power and focal length change. For two or more thin lenses close together, the optical power of the combined lenses is approximately equal to the sum of the optical powe... | Lens power |
c_cvifixoythxz | Similarly, the optical power of a single lens is roughly equal to the sum of the powers of each surface. These approximations are commonly used in optometry. | Lens power |
c_9fphamkcnch9 | An eye that has too much or too little refractive power to focus light onto the retina has a refractive error. A myopic eye has too much power so light is focused in front of the retina. This is noted as a minus power. | Lens power |
c_358ck776r8sr | Conversely, a hyperopic eye has too little power so when the eye is relaxed, light is focused behind the retina. An eye with a refractive power in one meridian that is different from the refractive power of the other meridians has astigmatism. This is also known as a cylindrical power. Anisometropia is the condition in... | Lens power |
c_qwqsl0g5rqzu | In optics, orange has a wavelength between approximately 585 and 620 nm and a hue of 30° in HSV color space. In the RGB color space it is a secondary color numerically halfway between gamma-compressed red and yellow, as can be seen in the RGB color wheel. The complementary color of orange is azure. Orange pigments are ... | Papaya whip |
c_zyth5z1rwys0 | Varieties of the color orange may differ in hue, chroma (also called saturation, intensity, or colorfulness) or lightness (or value, tone, or brightness), or in two or three of these qualities. Variations in value are also called tints and shades, a tint being an orange or other hue mixed with white, a shade being mixe... | Papaya whip |
c_aweyxrbmbqyl | In optics, photobleaching (sometimes termed fading) is the photochemical alteration of a dye or a fluorophore molecule such that it is permanently unable to fluoresce. This is caused by cleaving of covalent bonds or non-specific reactions between the fluorophore and surrounding molecules. Such irreversible modification... | Photobleaching |
c_qzy9bj8zgctz | In microscopy, photobleaching may complicate the observation of fluorescent molecules, since they will eventually be destroyed by the light exposure necessary to stimulate them into fluorescing. This is especially problematic in time-lapse microscopy. However, photobleaching may also be used prior to applying the (prim... | Photobleaching |
c_8v2fcoieu7gb | This can help improve the signal-to-noise ratio. Photobleaching may also be exploited to study the motion and/or diffusion of molecules, for example via the FRAP, in which movement of cellular components can be confirmed by observing a recovery of fluorescence at the site of photobleaching, or FLIP techniques, in which... | Photobleaching |
c_bg6xyyb1kgz5 | To a reasonable approximation, a given molecule will be destroyed after a constant exposure (intensity of emission X emission time X number of cycles) because, in a constant environment, each absorption-emission cycle has an equal probability of causing photobleaching. Photobleaching is an important parameter to accoun... | Photobleaching |
c_9xfz2mm2u9mg | For some dyes, lifetimes can be prolonged 10-100 fold using oxygen scavenging systems (up to 1000 seconds with optimisation of imaging parameters and signal-to-noise). For example, a combination of Protocatechuic acid (PCA) and protocatechuate 3,4-dioxygenase (PCD) is often used as oxygen scavenging system, and that in... | Photobleaching |
c_3ennslgeg16v | In optics, piston is the mean value of a wavefront or phase profile across the pupil of an optical system. The piston coefficient is typically expressed in wavelengths of light at a particular wavelength. Its main use is in curve-fitting wavefronts with Cartesian polynomials or Zernike polynomials. However, similar to ... | Piston (optics) |
c_3e7s5hr6vs4f | As phase values can only vary from zero to 2π, then repeat in either direction (termed phase wrapping), changing the piston coefficient changes the zero phase value contour locations across the wavefront. This property is critical to the operation of phase-measuring interferometers, which give not only the magnitude bu... | Piston (optics) |
c_xc9myb4fd99y | This changes the interferometric fringe patterns and allows direct calculation of the exact wavefront error. Piston and tilt are not actually true optical aberrations, as they do not represent or model curvature in the wavefront. Defocus is the lowest order true optical aberration. If piston and tilt are subtracted fro... | Piston (optics) |
c_f2qbbe4s0twd | In optics, polarization mixing refers to changes in the relative strengths of the Stokes parameters caused by reflection or scattering—see vector radiative transfer—or by changes in the radial orientation of the detector. | Polarization mixing |
c_607slky7xpy3 | In optics, polarization states are said to be orthogonal when they propagate independently of each other, as in vertical and horizontal linear polarization or right- and left-handed circular polarization. | Orthogonality |
c_xy0ur6f07rp7 | In optics, polarized light can be described using the Jones calculus, discovered by R. C. Jones in 1941. Polarized light is represented by a Jones vector, and linear optical elements are represented by Jones matrices. When light crosses an optical element the resulting polarization of the emerging light is found by tak... | Jones vectors |
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