It must be remembered that the fiber plates replace a glass window and a ( mica ) membrane, in addition to an optical output lens system.

* the width of the frequency range that can be transmitted by some element, e. g. an optical fiber

The Afghan Ministry of Communications signed a $ 64. 5 agreement in 2006 with China's ZTE on the establishment of a countrywide optical fiber cable network.

At the regional cable television headend | headend, the TV channels are sent multiplexed on a light beam which travels through optical fiber trunklines, which fan out from distribution hubs to optical nodes in local communities.

Most systems use hybrid fiber coaxial ( HFC ) distribution ; this means the trunklines that carry the signal from the headend to local neighborhoods are optical fiber to provide greater bandwidth and also extra capacity for future expansion.

The fiber trunkline goes to several distribution hubs, from which multiple fibers fan out to carry the signal to boxes called optical nodes in local communities.

At the optical node, the light beam from the fiber is translated back to an electrical signal and carried by coaxial cable distribution lines on utility poles, from which cables branch out to subscriber residences.

This process results in an unusually mechanically simple laser optical amplifier for signals transmitted by fiber optics.

In addition to optical fiber lasers, a large variety of medical applications ( i. e. dermatology, dentistry ) utilize the erbium ion's 2940 nm emission ( see Er: YAG laser ), which is highly absorbed in water in tissues, making its effect very superficial.

Telecommunications engineering focuses on the transmission of information across a channel such as a coax cable, optical fiber or free space.

In most cases, the cables are just changed from electrical to optical fiber cables.

Rapid improvements, innovations, and diversification in communications technology, including optical fiber cables, communications satellites, and fax machines, led to rapid growth of the communications industry in the 1980s.

The beam in the cavity and the output beam of the laser, when travelling in free space ( or a homogenous medium ) rather than waveguides ( as in an optical fiber laser ), can be approximated as a Gaussian beam in most lasers ; such beams exhibit the minimum divergence for a given diameter.

In 1976, T. P. Pearsall created the first high-brightness, high-efficiency LEDs for optical fiber telecommunications by inventing new semiconductor materials specifically adapted to optical fiber transmission wavelengths.

: Uses the physical change of an optical fiber to detect strain due applied pressure.

built in April 1992 and the country ’ s first optical fiber cable network consisting of 480

China ’ s 2. 7 million kilometers of optical fiber telecommunication cables by 2003 assisted greatly in the modernization process.

Work in 1998 verified the initial results, and in August 2004 increased the distance of teleportation to 600 meters using optical fiber.

With the viscosity of a sol adjusted into a proper range, both optical quality glass fiber and refractory ceramic fiber can be drawn which are used for fiber optic sensors and thermal insulation, respectively.

The concept of the strain energy as a Gibbs function difference Af and exerting a force normal to the shearing face is compatible with the information obtained from optical birefringence studies of fluids undergoing shear.

Flatness may now monopolize everything, but it is a flatness become so ambiguous and expanded as to turn into illusion itself -- at least an optical if not, properly speaking, a pictorial illusion.

) An authentic diffraction pattern is always obtained and optical properties are frequently checked.

It should be noted, however, that the paraxial resolution is quite similar for both electron optical systems.

The electron optical system ( see fig. 14-1 ) is based in principle on the focusing action of concentric spherical cathode and anode surfaces.

It is clear from this discussion that cosmologists of every persuasion look hopefully toward the day when a man-made satellite can be equipped with optical devices which will open up new vistas to science.

As with many scientific fields, strict delineation can be highly contrived and atomic physics is often considered in the wider context of atomic, molecular, and optical physics.

The and convention for amino acid configuration refers not to the optical activity of the amino acid itself, but rather to the optical activity of the isomer of glyceraldehyde from which that amino acid can, in theory, be synthesized (- glyceraldehyde is dextrorotary ;-glyceraldehyde is levorotatory ).

Alexander's band, an optical phenomenon, is named after him.

Shot noise is a type of electronic noise that occurs when the finite number of particles ( such as electrons in an electronic circuit or photons in an optical device ) is small enough to give rise to statistical fluctuations in a signal.

Atomic absorption spectroscopy ( AAS ) is a spectroanalytical procedure for the quantitative determination of chemical elements employing the absorption of optical radiation ( light ) by free atoms in the gaseous state.

An optical aberration is a departure of the performance of an optical system from the predictions of paraxial optics.

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.

Defocus is the lowest-order true optical aberration.

The elementary theory of optical systems leads to the theorem: Rays of light proceeding from any object point unite in an image point ; and therefore an object space is reproduced in an image space.

The Gaussian theory, however, is only true so long as the angles made by all rays with the optical axis ( the symmetrical axis of the system ) are infinitely small, i. e. with infinitesimal objects, images and lenses ; in practice these conditions are not realized, and the images projected by uncorrected systems are, in general, ill defined and often completely blurred, if the aperture or field of view exceeds certain limits.

Math., 1858 ) and Ernst Abbe showed that the properties of these reproductions, i. e. the relative position and magnitude of the images, are not special properties of optical systems, but necessary consequences of the supposition ( in Abbe ) of the reproduction of all points of a space in image points ( Maxwell assumes a less general hypothesis ), and are independent of the manner in which the reproduction is effected.

In pinhole projection, the magnification of an object is inversely proportional to its distance to the camera along the optical axis so that a camera pointing directly at a flat surface reproduces that flat surface.

* One application of autocorrelation is the measurement of optical spectra and the measurement of very-short-duration light pulses produced by lasers, both using optical autocorrelators.

Settled phosphors, as generally used in image intensifiers, have low optical contact with the substrate surface, hence Af shall be assumed.

The accurate range of pistols is generally limited to, while most rifles are accurate to using iron sights, or longer ranges using optical sights.

Although traditionally considered one of seven colors of the rainbow or the optical spectrum, modern color scientists do not usually recognize indigo as a separate division and generally classify wavelengths shorter than about 450 nm as violet.

There exist other physical processes that can lead to a shift in the frequency of electromagnetic radiation, including scattering and optical effects ; however, the resulting changes are distinguishable from true redshift and not generally referred as such ( see section on physical optics and radiative transfer ).

A light-adapted eye generally has its maximum sensitivity at around 555 nm ( 540 THz ), in the green region of the optical spectrum ( see: luminosity function ).

Due to the sophisticated polishing and tuning procedures that may be incorporated into optical connector manufacturing, connectors are generally assembled onto optical fiber in a supplier ’ s manufacturing facility.

In the case of photons this channel is generally either an optical fibre or simply free space.

The term double star may be used synonymously with binary star, but more generally, a double star may be either a binary star or an optical double star which consists of two stars with no physical connection but which appear close together in the sky as seen from the Earth.

Optical infinity — This was achieved by adjusting the focal distance so that it was above what is sometimes referred to as " optical infinity ", which is generally taken as about 30 ft or nine m. In this context, " Optical Infinity " is the distance at which, for the average adult person, the angle of view of an object at that distance is effectively the same for both the left and right eyes.

CD is closely related to the optical rotatory dispersion ( ORD ) technique, and is generally considered to be more advanced.

In addition, the application of MCD spectroscopy greatly improved the level of understanding in the ferrous non-heme systems because of the direct observation of the d – d transitions, which generally can not be obtained in optical absorption spectroscopy owing to the weak extinction coefficients and are often electron paramagnetic resonance silent due to relatively large ground-state sublevel splittings and fast relaxation times.

This results in most fansubs having similar file sizes: 175 MB, 233 MB, and 350 MB are generally treated as the " standard " sizes for a fansub file because they divide evenly into 700 MB, the size of a typical CD-R. As the price of Hard disk drives have decreased while their storage capacity has increased, modeling fansub filesizes after optical media constraints has become largely unimportant.

The transmitters in optical fiber links are generally light-emitting diodes ( LEDs ) or laser diodes.

Free Space Optics ( FSO ) systems are generally employed for ' last mile ' communications and can function over distances of several kilometers as long as there is a clear line of sight between the source and the destination, and the optical receiver can reliably decode the transmitted information.

Hans Lippershey is generally credited with the earliest recorded design for an optical telescope ( a refracting telescope ) in 1608, although it is unclear if he invented it.

Unlike optical telescopes which possess simple aluminized parabolic surfaces ( mirrors ), X-ray telescopes generally use a Wolter telescope consisting of nested cylindrical paraboloid and hyperboloid surfaces coated with iridium or gold.

The shortest directly produced optical pulses are generally produced by Kerr-lens mode-locked Ti-sapphire lasers, and are around 5 femtoseconds long.

* Optical Data Storage uses lasers, and the emerging technology of 3D optical data storage generally relies on nonlinear photochemistry.

This includes some kinds of microscopy to examine external surfaces in detail, although sample preparation techniques for metallography, optical microscopy and electron microscopy are generally destructive as the surfaces must be made smooth through polishing or the sample must be electron transparent in thickness.

The optical focus, linearity, brightness and clarity of an overhead generally cannot match that of a video projector primarily due to the plastic fresnel lens, which can only approximate what would normally be an extremely large and heavy glass lens.

Although early developers and users of distributions built on top of the Linux kernel could take advantage of cheap optical disks and rapidly declining prices of CD drives for personal computers, the Linux distribution CDs or " distros " were generally treated as a collection of installation packages that must first be permanently installed to hard disks on the target machine.

The various optical elements in the beamlines are generally packaged into Line Replaceable Units ( LRUs ), standardized boxes about the size of a vending machine that can be dropped out of the beamline for replacement from below.

An ionization type smoke detector is generally cheaper to manufacture than an optical smoke detector ; however, it is sometimes rejected because it is more prone to false ( nuisance ) alarms than photoelectric smoke detectors.