Photonics Dictionary: S

STED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence microscopy that surpasses the diffraction limit, enabling the visualization of...

In sensitometric testing, a series of areas progressing by equal density steps (usually the increments between steps are equal to the logarithm of the square root of two). They are commonly used in...

A type of camera that has scales or other arrangements by which successive exposures can be lined up and equally spaced on a sheet of film. It is used in the preparation of microfiche copies of...

A positioning drive that rotates a fraction of a 360° turn when the motor coils are activated, resulting in linear or rotary motion. They are generally one of two types, either variable...

A method of creating real three-dimensional models by using lasers driven by CAD software. In contrast to the normal practice of removing material, this process polymerizes a liquid to quickly...

The use of a specialized optical microscope designed to provide a more three-dimensional view of a sample. Stereomicroscopy usually uses reflected light and provides enhanced depth perception via the...

The photographing of a scene from positions corresponding to the locations of both eyes. A viewing device is used to present one picture to each eye for fusion of the retinal images, giving a...

The fine scratches formed when, in hand centering, the forked stick used to move the lens on the chuck marks the rotating lens surface.

In Stimulated Brillouin Scattering (SBS), an incident photon (usually laser light) interacts with acoustic phonons in a medium. The energy and momentum of the incident photon are transferred to the...

Radiation similar in origin to spontaneous emission but determined by the presence of other radiation having the same frequency. Because the phase and amplitude of the stimulated wave depend on the...

The process of creating a large, panoramic image by aligning and joining a set of smaller images. Image processing is used to obscure the edges between the smaller images, producing a seamless...

Stochastic optical reconstruction microscopy (STORM) is a superresolution microscopy technique that enables imaging of biological specimens at resolutions beyond the diffraction limit of conventional...

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

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

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...

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...

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...

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...

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...

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 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...

Characterizes an Earth-orbiting satellite whose orbit plane is near polar and positioned at an altitude that allows it to pass over every spot on the Earth at identical local sun time twice a day.

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...

An instrument consisting essentially of a photoelectric cell filtered to respond to a specified wavelength region, an amplifier of sufficient gain to provide power enough to control movement of a...

Observed phenomenon in laser pulses in which a large number of excited electrons are created and in which multiphoton processes have produced seed electrons, and excited neutral atoms are...

Superluminal transmission refers to the hypothetical process of transmitting information faster than the speed of light, which is commonly denoted as superluminal or faster-than-light (FTL)...

Superresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by the diffraction of light. In the context of imaging, it is a set of...

A form of liquid crystal in which the 90° twist of the twisted nematic phase has been increased to 180° or more, resulting in higher contrast and a wider viewer angle in the display.

1. In optics, one of the exterior faces of an optical element. 2. The process of grinding or generating the face of an optical element.

A large table with an accurately designed plane surface used to test other surfaces, or to provide a true surface for accurately locating a testing fixture. Most commonly made of granite.

Surface-enhanced Raman scattering (SERS) is a powerful analytical technique that enhances the Raman scattering signal of molecules adsorbed on or near certain nanostructured surfaces. Raman...

A surface-mount device (SMD) is an electronic component that is mounted directly onto the surface of a printed circuit board (PCB) rather than being inserted into holes drilled in the board (as with...

In a laser, the voltage necessary to sustain a constant operating current, somewhat less than that needed for start-up.

Swept-source optical coherence tomography is an imaging technique used in medical diagnostics, particularly in ophthalmology, to visualize and analyze the internal structures of biological tissues,...

A swept-source laser, also known as a wavelength-swept laser, is a type of laser that rapidly and continuously changes its emission wavelength over time. This continuous wavelength tuning is achieved...

A standard for fiber optic telecommunications interfaces, with a 1300-nm data link operating over single-mode fiber at data rates of 52, 155 and 622 Mb/s.

The technique of generating ultrashort -- down to subpicosecond -- pulses by pumping a dye laser with mode-locked laser pumps with cavity lengths the same as, or a submultiple of, that of the dye...

A mode of transmission whereby the sending and receiving stations operate continuously at a fixed relationship of phase and frequency, generating signals to control the timing of the data that are to...

A synchrotron is a type of particle accelerator that uses magnetic fields to steer charged particles, typically electrons or positrons, in a closed, circular or elliptical path. The name synchrotron...

Abbreviated SoC. A single chip containing all the electronic circuits required for a complete, working product. SoCs are similar to microcontroller technology but provide additional components. A SoC...