PowerPhotonic Ltd. - Bessel Beam Generator LB 6/24

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PI Physik Instrumente - FSM for FSOC MR LW 6/24

626 terms

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sextant

A handheld navigational instrument used to measure the elevation angle of celestial bodies such as the sun. An image of the sun is viewed through a small telescope via two plane mirrors so that any...

Shack-Hartmann wavefront sensor

The Shack-Hartmann wavefront sensor is an optical device used for measuring the wavefront aberrations of an optical system. It is widely used in adaptive optics systems to correct distortions and...

shading

1. The sorting of lenses by their color. 2. In an optical system, an irradiance or brightness gradient in the image that is not present at the object.

shadow mask -> aperture mask

Also known as a shadow mask, a perforated plate placed between the focusing and accelerating electrodes, and the tricolor phosphor screen in a color-television tube.

shadow mask tube

A type of color-generating cathode-ray tube that uses a shadow mask, a thin perforated electrode, located close to the display screen. Each hole in the mask coincides with a triad of three phosphor...

shadowgraph

A method of demonstration or examination using a point source illumination without the use of any projection lens between the object and its shadow, the shadow being cast on a distant screen.

shallow

A term used to denote a concave surface having too long a radius of curvature. That is, its negative power is too small or low.

Shannon's sampling theorem -> finite sampling theorem

A finite version of Shannon's sampling theorem that states that a class of functions can be reconstructed exactly by a sufficient number of spectral samples; the reconstructed function is an explicit...

sharp

A term used to describe a convex surface having too short a radius of curvature. To correct this condition, material is cut from the outer portion of the polishing tool.

sharp height

The distance between the base and the vertex before the edging of a prism.

sharpness index

A function of the intensity distribution in an image aberrated by a quadratic curvature wavefront distortion.

shear

Image distortion that occurs when the axes of the original image are not perpendicular in the resulting image, making the resulting image appear slanted. Shear can be caused by movement of the...

shearing interferometer

An interferometer in which interference is produced between wavefronts that are sheared in the sample object by a small lateral distance.

sheathing -> jacket

The outer material that surrounds and protects the buffered and unbuffered fibers in an optical cable.

sheet grating

A three-dimensional grating designed with thin metal sheets to remain opaque to all but one specific and predetermined wave.

sheet polarizer

A sheet of plastic material containing microscopic crystals of herapathite or some other similar substance that transmits light polarized in one direction, but absorbs light polarized in a...

shift register -> transport shift register

The element in a charge-coupled device that receives the charge packets transferred from the line of sensor sites and then delivers the image data to the device's output circuitry.

shining -> clearing

Also called shining. Grinding and polishing one surface of a blank to permit a more thorough examination for quality.

shock wave

Interruption in the normal flow of a plasma or fluid characterized by sharp rises in velocity, temperature and pressure. As the shock passes into a gaseous compound, gas particles are heated and...

short finish

A term that describes an incomplete polish.

short wavelength infrared

Short wavelength infrared (SWIR) refers to the portion of the infrared spectrum that encompasses wavelengths roughly between 1,000 and 3,000 nanometers (nm). In the electromagnetic spectrum, infrared...

short-arc lamp

A compact high-pressure light source in which an electrical discharge between electrodes spaced no more than 12 mm apart occurs in a xenon or other gas medium, providing a visible light resembling a...

short-flash light source

An electronic flash tube in which the flash recurs at a frequency extending to many thousands per second. A stroboscopic light source is a short-flash light source.

short-focus lens -> wide-angle lens

A wide-angle lens is a type of camera lens that has a shorter focal length than a standard or normal lens, allowing it to capture a broader field of view. Wide-angle lenses are characterized by their...

short-wave pass filter

A filter that is transparent to shorter wavelengths, but opaque to longer wavelengths.

short-wave radiation

Characterizes the significant solar radiation at the surface of the earth, so named because its spectral range extends only from 0.3 to 2.8 µm.

shot noise

Noise generated by the random variations in the number and velocity of the electrons from an emitter.

shunt resistance

In a silicon photodiode, the dynamic resistance (dv/d1) of the junction at zero volts.

shutter

A mechanical or electronic device used to control the amount of time that a light-sensitive material is exposed to radiation.

shutter speed tester

A device used to measure the opening time of a shutter. The most common devices depend on the charging or discharging of an electrical condenser, or on the production of a curve of open area against...

Systeme Internationale d'Unites, the international metric system of units.

side mode suppression ratio

The relation of power between center peak longitudinal mode with the nearest higher order mode.

side-lit cable

A type of fiber optic cable that emits light from its sides along its length.

sidereal time

Frequently used in astronomical measurement, it is based on the diurnal rotation of a star relative to the fixed stellar system.

siemens

The electric conductance of a conductor in which a current of 1 ampere is produced by an electric potential difference of 1 volt.

sign conventions

A convention that defines specific dimensions of an optical system, such as the image distance or radius of curvature of a lens or mirror, as negative or positive to facilitate calculations based on...

signal level

Calculation of peak and average transmission power at a given point along an optical fiber or cable.

signal period

Also referred to as the width of the dark pulse. This is the time interval between the instant the particle approaches the beam and the instant the particle leaves the beam.

signal-induced noise

Noise generated in the flow of current in the photomultiplier, produced by the intentional or controlled application of optical power to the photocathode.

signal-to-noise ratio

The ratio of the power in a desired signal to the undesirable noise present in the absence of a signal.

silica -> silicon dioxide

An abundant material found in the form of quartz and agate and as one of the major constituents of sand. The silicates of sodium, calcium, and other metals can be readily fused, and on cooling do not...

silicon -> optical-grade silicon

The element that resembles a lightweight metal, but when very pure, has a very high electrical resistance and is transparent to the infrared between about 0.5 and 15 µm.

silicon carbide light-emitting diodes

Silicon carbide (SiC) light-emitting diodes (LEDs) are semiconductor devices that emit light when an electric current is applied to them. These LEDs are made using silicon carbide as the...

silicon cell

A solid-state device, composed of silicon, that is used to convert radiation into electrical energy.

silicon dioxide

silicon monoxide

A material used as a protective layer on an aluminized or silvered mirror. It is evaporated on the mirror as a thin layer, and after exposure to the air the monoxide tends to become silicon dioxide...

silicon photodiode

A silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector specifically designed for detecting and measuring light intensity. Silicon...

Silsbee effect

The ability of an electrical current to destroy superconductivity by means of the magnetic field generated by the current. The temperature of the material is not raised, and the effect is identical...

silver halide emulsion

An emulsion in which grains of the photosensitive material silver halide are deposited. Each grain, when exposed to light, either develops or fails to develop as a unit, leaving a dark or clear...

silver spots

Spots in a polished glass surface that are opaque and have a silvery, metallic reflection.

Photonics DictionaryDefinitionsS