Photonics Dictionary

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.

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

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;...

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

A high-speed cine camera used to record, on a continuously moving film, very brief events such as a flash of light. The image is recorded as a continuous image, not as a series of individual frames.

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 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...

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...

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

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

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...

Supercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the near-infrared or even mid-infrared regions of the electromagnetic...

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...

(SALI) A type of spectroscopy in which neutral atoms or molecules are ionized by an excimer laser beam and then measured by a time-of-flight mass spectrometer.

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...

A semiconductor laser diode that emits light perpendicular to the active region. The output radiation is taken through the surface as opposed to through a cleaved mirror.

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...

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 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...

Radiation emitted by electrons when they travel in circular orbits at speeds close to that of light. Synchrotron radiation occurs in the x-ray and ultraviolet regions of the spectrum. Once considered...

An imaging technique in which an object moving through an interference field formed in space scatters light and is spatially recorded on a photographic film as a hologram. If the interference field...

One lumen-second, the SI unit of the quantity of light.

States that in interferometers in which the separation of the maxima is equal to the half-value width, a slight drop in intensity between fringes is distinguishable and the fringes can be considered...

A telescope lens is a primary optical component of a telescope system that gathers and focuses light to form an image. It is typically a curved, transparent piece of glass or other optical material...

A characteristic of laser output, calculated by dividing the speed of light by the linewidth of the laser beam. The temporal coherence length of different lasers thus varies from a few centimeters to...

Characteristic of deflected light power defined as the quadratic invariant function of the video signal amplitude.

A photoconductive cell that uses thallium oxysulfide as the light-sensitive medium.

A thermal-infrared camera, often referred to simply as a thermal camera, is a type of imaging device that detects infrared radiation emitted by objects due to their temperature. Unlike traditional...

Thermal interface materials (TIMs) are substances or compounds used to enhance the thermal conductivity between two surfaces in contact. These materials are primarily employed in electronic devices,...

Thin-film coatings are layers of material applied to the surface of an object or substrate, typically to modify its optical, electrical, or mechanical properties. These coatings are composed of thin...

A solar cell that is lightweight and flexible because of its construction by vacuum deposition of a semiconductor material (e.g., gallium arsenide or cadmium sulfide) onto a thin metal or plastic...

A transparent dielectric film, bounded by material of a lower index of refraction, capable of guiding light.

Three-photon microscopy is an advanced imaging technique that belongs to the family of multi-photon microscopy methods. It is used in biological and medical research to capture high-resolution images...

1. Voltage at which a PN junction begins to pass a current. 2. In a solid-state lamp, the voltage at which light is first emitted.

A method of scanning in which a frame transfer device produces a continuous video image of a moving object by means of a stack of linear arrays aligned with and synchronized to the movement of the...

Time-correlated single photon counting (TCSPC) is a technique used in photon counting applications, particularly in the field of experimental physics, biophysics, and fluorescence lifetime imaging...

Time-lapse optical coherence tomography (OCT) refers to a medical imaging technique that captures a series of sequential OCT scans over time, allowing for the dynamic observation and monitoring of...

A time-to-amplitude converter (TAC) is an electronic circuit that converts a time interval between two events into an amplitude or voltage signal. TACs are commonly used in various scientific and...

Tip-enhanced Raman scattering (TERS) is a powerful technique that combines Raman spectroscopy with the enhanced spatial resolution provided by a sharp metallic or dielectric tip. TERS allows...

The study of the optical properties of living tissue. Increased understanding of the behavior of light in this varied, turbid medium, especially its scattering and absorption characteristics, is...