Photonics Dictionary: S

The determination of what, how much and in what proportions chemicals must be combined to produce the desired reactions and products.

A line of the Raman spectrum that fulfills Stokes' law because it possesses a wavelength that is greater than the radiation that stimulated the luminescence of the source.

The parameters, relative to polarized light and the Poincaré sphere, that are usually represented as: I, the intensity of the light beam; M, that part of the beam polarized in the horizontal plane;...

Relative to radiation wavelength, the law that states that the wavelength of luminescence stimulated by radiation always surpasses that of the stimulating radiation.

To reduce the size of a lens aperture, which increases the depth of field.

A motion-picture camera that can be advanced one frame at a time, either randomly or at set intervals. Used in animation and time-lapse photography.

Interval between cutting off a photoconductor's signal and the fall of current output to 90 percent.

A cathode-ray tube combined with an electrostatic storage unit that is used to introduce, store and retrieve information translated into electric charge form.

A term referring to the pre-exposed hologram of the subject used in holographic interferometry.

The determination of axially symmetric and asymmetric refractive-index distributions by use of interferometry carried out on the basis of the approximation of a straight path of rays passing through...

In optics, the mechanical tension, compression or shear in optical glass due to internal stress caused by improper cooling or annealing during manufacture of the glass or the subsequent working of...

A viewer that uses the transmittance of polarized light through glass or a similar medium to examine strained regions. See polariscope.

A streak camera is a specialized instrument used to capture and analyze ultrafast phenomena, such as extremely short pulses of light or rapidly changing events. Unlike traditional cameras that...

The ratio of the illuminance at the peak of the diffraction pattern of an aberrated point image to that at the peak of an aberration-free image as formed by the same optical system.

A strand of aramid yarn, steel or fiberglass in an optical cable intended to prevent bending or stretching that would damage the transport medium.

Birefringence of materials that is induced or altered by stress fields.

A type of fatigue found in optical fibers, caused by water or another corroding agent.

In polarization-preserving optical fibers, the element used to induce birefringence. The SAP is highly doped to provide a different coefficient of expansion from the rest of the fiber material; when...

A method of polishing an aspheric surface by mechanically distorting the optic while polishing the surface to a perfect sphere. When the stress is released, the substrate assumes the desired aspheric...

An imperfection in optical glass consisting of a distinct streak of transparent material having a slightly different refractive index from the body of glass. It is caused by improper mixing of...

Wavy transparent line in a sheet of glass appearing as though a thread of glass had been incorporated into the sheet.

In rudimentary form, this technology consists of diffusion of a PN junction through a mask of silica, over which a contact is applied.

A tool used to remove the outer cladding of an optical fiber without damaging the fiber core.

A type of sheathing for fiber optic cable that incorporates a coil of metal; often used in harsh environments.

A device that produces brief flashes of light for observing the behavior of an object during a short interval. One of the most effective means for accomplishing this is a gaseous tube energized by...

A pulsed interferometer that permits the continuous quantitative mapping of the surface deformation of an adaptive optical element (e.g., a deformable mirror) and provides the capability for...

An electronic flash tube capable of repeated operation at hundreds or thousands of flashes per second for long periods.

A specified cold-cathode gas tube used to apply a short-duration, high-power arc for a stroboscope.

The pattern formed by a character generation cathode-ray tube system, in which the characters are composed of a sequence of line segments (strokes) generated by the electron beam motion with time...

An approach to character recognition based on the structure of the character to be identified (number of straight lines, bays, holes, etc.); used where simple matching is not viable, as in...

Structural color refers to coloration in materials that is not caused by pigments or dyes but is instead a result of the physical structure of the material. In structural color, the interaction of...

The mean square difference in a spatial parameter at points spaced a given distance.

Structured illumination microscopy (SIM) is an advanced optical imaging technique used in microscopy to enhance the resolution of images beyond the diffraction limit imposed by traditional light...

The projection of a plane or grid pattern of light onto an object. It can be used for the determination of three-dimensional characteristics of the object from the observed deflections that result.

The pattern used as a probe in morphological image processing to manipulate the size and shape of objects in an image.

The distance between two focal lines in an astigmatic image produced by a lens or mirror.

A method used in surface quality testing for accurate positioning and rotation of metal spheres about an axis or fixed point in space that involves a sliding contact between the indicator and tip and...

A measuring instrument used for surface profiling and quantifying the roughness of a material. The stylus is placed on the surface of the material at a given contact force, then is moved laterally...

A copolymer of styrene and acrylic used in molded optical components; it has a high refractive index and a low coefficient of thermal expansion.

That portion of the telecommunications network that runs from a local central telephone to the subscriber premises.

In a microscope, the optical assembly that focuses light on the specimen and into the objective.

A substrate refers to a material or surface upon which another material or process is applied or deposited. In various fields, such as electronics, biology, chemistry, and manufacturing, the term...

The basic process of color photography whereby colors are subtracted from white light by means of filters, making all colors and intensities available.

Cyan, magenta and yellow. They are called subtractive because they each subtract one color by absorbtion and reflect the two others of the red, green, blue color primaries. Cyan absorbs red, magenta...

Family of deterministic models of plant canopy reflectance that provides deterministic formulation for each necessary parameter and a method to calculate reflectance as a function of sun and observer...

Heat loss determined by the sum of rising and falling slopes at a constant temperature.

Controlled beam technology that introduces beams of sunlight through holes in a roof that are relayed throughout the building by a series of mirrors and lenses. Ideally, cool lighting is obtained by...