Photonics Dictionary: S

A saturable absorber is a type of optical device that exhibits variable absorption properties depending on the intensity of incident light. In essence, it becomes less absorbent as the light...

1. The decrease of the absorption (or gain) coefficient of a medium near some transition frequency when the power of the incident radiation near that frequency exceeds a certain value. As long as the...

Scientific complementary metal-oxide semiconductor (sCMOS) refers to a type of image sensor technology specifically designed for scientific and industrial imaging applications. Unlike traditional...

A scintillation crystal, also known simply as a scintillator, is a material that emits light when it interacts with ionizing radiation such as gamma rays, x-rays, or charged particles. The emitted...

A scintillation detector is a radiation detection device that utilizes scintillation crystals to detect and measure ionizing radiation, such as gamma rays, x-rays, or charged particles. It consists...

Second-harmonic generation (SHG) is a nonlinear optical process that occurs when two photons with the same frequency combine within a nonlinear material, resulting in the generation of a new photon...

Second-order nonlinear optical properties refer to a class of phenomena exhibited by certain materials in response to intense light, typically in the realm of optics and photonics. Nonlinear optical...

Characteristic of dissimilar metals in thermoelectric solar cells whereby separate junctions exhibiting distinct temperatures transform incident voltage into a current.

Seidel aberrations refer to a set of monochromatic aberrations in optical systems, named after the German mathematician and physicist Ludwig von Seidel. These aberrations describe deviations from...

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...

An instrument that uses a blackened silver-disc reflector with a shutter to create temperature fluctuations that are proportional to the intensity of the solar radiation incident upon it. Using the...

Single molecule localization microscopy (SMLM) is a group of super-resolution microscopy techniques that surpass the diffraction limit of traditional optical microscopes, allowing for the...

A single-photon avalanche diode (SPAD) is a specialized type of photodetector designed to detect extremely weak optical signals, down to the level of single photons. SPADs are widely used in...

A crystal, glass, or quartz slicing and cutting machine is a specialized piece of equipment used in the manufacturing process to precisely cut and slice materials such as crystals, glass, and quartz...

The incident ray, the normal to the refracting surface at the point of incidence of the ray at the surface, and the refracted ray all lie in a single plane. The ratio of the sine of the angle between...

Solar radiation intensity existing in free space at the mean solar distance of the Earth. Commonly expressed in g cal cm-2min-1, the constant is equal to the amount of incident radiation -- in unit...

Device that uses a coherent reference wave to record the interference patterns produced by incident ultrasonic waves on an object.

The spatial distribution of incident and collected flux contained in the analysis of reflectance, transmittance or densities.

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of light in two dimensions, typically in the form of an array. SLMs are...

Average wavelength usually determined for light-transmitting devices by taking a weighted average for each wavelength of the spectral energy distribution of incident light, transmittance of the...

Characteristic of the relationship between photoelectric activity and the wavelength of incident radiation.

The light flash, produced in flash photolysis, that is triggered within a second discharge tube by the third electrode. It is to be differentiated from the photolysis flash which is triggered within...

Spectroscopy is a technique used in the study of interactions between matter and electromagnetic radiation. It involves measuring and analyzing how different materials absorb, emit, or scatter light,...

The field of view seen through some types of coincidence rangefinders. It is formed by the juxtaposition of opposite halves of the images produced by two objectives, the half-images being separated...

A rangefinder similar to a pair of binoculars with a long base, a dot or other wander mark provided in each eyepiece field, together forming an apparent point in space. When one dot is moved...

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...

Light from a pulsed laser focused into nonsaturable absorbing fluid that generates a strongly backscattered light beam with a frequency higher than that of the incident light.

Also known as Fresnel reflection. That portion of the incident radiation that is reflected from the surface of a refractive material. It is a function of the refractive index of the material. At...

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...

Surface-enhanced Raman spectroscopy (SERS) is an analytical technique that combines the principles of Raman spectroscopy with the enhancement provided by nanostructured metallic surfaces. Raman...