Photonics Dictionary

Wide-field, low-magnification device that consists of two compound microscopes focused on a single object, producing an erect three-dimensional image.

The perception of depth due to binocular vision.

A small instrument containing a picture support and a pair of magnifying lenses so arranged that the left eye sees only the picture taken with the left lens of the stereo camera, and the right eye...

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.

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...

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;...

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

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...

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...

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...

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...

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...

A metal, alloy or compound that loses its electrical resistance at temperatures below a certain transition temperature referred to as Tc. High-temperature superconductors occur near 130 K, while...

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...

A meniscus that is often fitted before a camera lens to permit focusing on near objects.

(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.

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.

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.

A technique of optical storage whereby information is encoded by molecular alterations in the interaction between the optical layer and the substrate.

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...

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 detector sensitive only to signals close to or at a particular frequency that is the same as the frequency of a control signal applied independently. The synchronous detector also is...

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...

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...

The equivalent f number of a fictitious lens that has a circular opening and 100 percent transmittance, which would give the same central illumination as the lens being considered: where...

In optics, a shape often given to the leading edge of a projectile. In any side view it appears as a pointed arc, while any cross section perpendicular to its long axis appears as a circle.

In television, a lateral displacement of the lines from their normal position due to the instability of a synchronizing circuit. Visually, it appears as though parts of the images had been torn away.

There are three types of telecentric lenses: -Image-space telecentric lenses are those in which the aperture stop is located at the front focus, resulting in the chief rays being parallel to the...

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...

The base used to hold an astronomical telescope. It may be either altazimuth, with horizontal and vertical axes of rotation, or equatorial, with one axis parallel to the Earth's axis of rotation and...

A television receiver that receives the signals generated by a television camera directly, or remotely through a radio signal. It may be used to continuously check image and sound reception; as a...

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...

A terahertz spectrometer is a scientific instrument used to measure and analyze the properties of materials in the terahertz frequency range, typically spanning from about 0.1 to 10 terahertz (THz),...

Terahertz (THz) refers to a unit of frequency in the electromagnetic spectrum, denoting waves with frequencies between 0.1 and 10 terahertz. One terahertz is equivalent to one trillion hertz, or...

A transparent block shaped accurately to reverse curvatures of the components it is used to test. By contacting an accurately finished negative lens shape with a newly made positive, the conformity...