Photonics Dictionary

Plasmonics is a field of science and technology that focuses on the interaction between electromagnetic radiation and free electrons in a metal or semiconductor at the nanoscale. Specifically,...

A lens made from transparent plastic material. Lenses over 31/2 in. in diameter are usually machined, ground and polished. Smaller lenses are usually injection molded, the mount surrounding the lens...

1. With respect to angular subtense, a source of light, such as a star, that is very small. In a lab, a point source may be simulated by imaging a large source onto and through a pinhole, or by...

A lamp, usually incandescent, that has a very compact filament, permitting a greater concentration of emitted light, aided by the use of small apertures and appropriate reflectors.

The point spread function (PSF) is a fundamental concept in imaging that describes the response of an imaging system to a point source or point object. It characterizes how a single point of light is...

The polymerase chain reaction (PCR) is a widely used molecular biology technique used to amplify a specific segment of DNA (deoxyribonucleic acid) through a series of temperature-controlled cycles....

Process of synthesizing long molecular chain materials (polymers) by reaction of many small molecules (usually thousands) called monomers.

A device used to project a small area of light on a screen for indication.

The underexposure caused by the diffraction of light passing through small openings spaced closely together in masks used in photolithography.

The compression and intensification of a laser pulse of a specific width into a smaller pulse width. A spherical cavity, in conjunction with a beam compressor, is efficient for pulse amplification....

The term quantum refers to the fundamental unit or discrete amount of a physical quantity involved in interactions at the atomic and subatomic scales. It originates from quantum theory, a branch of...

Quantum confinement refers to the phenomenon in quantum mechanics where the motion of charge carriers, such as electrons or holes, is restricted to a region of space that is smaller than their...

Essentially, a hologram of a hologram, in which the first-generation hologram is masked with a narrow slit. During image reconstruction, the slit operates as the exit pupil in image space. The...

When light is transmitted through matter, part of the light is scattered in random directions. A small part of the scattered light has frequencies removed from the frequency of the incident beam by...

A flexible fiber cable with a small diameter that transports light from the excitation laser to the target. Used in Raman spectroscopy, the probe is capable of obtaining high-quality data at high...

Raman spectroscopy is a technique used in analytical chemistry and physics to study vibrational, rotational, and other low-frequency modes in a system. Named after the Indian physicist Sir C.V. Raman...

Rayleigh scattering is a phenomenon that occurs when light waves interact with particles or molecules that are much smaller than the wavelength of the light. It is named after the British scientist...

A galvanometer having a small mirror that is mounted on a moving element and that reflects a light beam onto a scale.

The optical phenomenon in which white light dispersed by small particles in suspension appears blue when viewed through a suitable Nicol prism.

A chart on paper or glass containing a series of sets of lines at progressively smaller spacing and used to ascertain the limiting number of lines per millimeter that an optical system is capable of...

A type of ultrasensitive laser spectroscopy that can detect quantities as small as a single atom of some substances and that can differentiate between isobars of different elements.

A small erect-image telescope for use as a sighting device on a rifle. The chief requirement is a long eye relief to avoid damage to the eye due to recoil. The power may lie anywhere between 1 and...

A ring laser gyroscope (RLG) is a type of gyroscope that uses laser light to detect and measure changes in orientation. It operates based on the Sagnac effect, which is a fundamental principle of...

An interferometric method for describing the surface shape of large coated or uncoated optical flats. The procedure uses a commercially available small-aperture phase-shifting interferometer for...

A circular optical wedge (prism of small refracting angle) mounted to be rotated in the path of light rays to divert the line of sight to a restricted degree.

One of the types of change in the energy levels of molecules or atoms in a laser that can result in lasing action. Because the energy levels between rotational states are small, such lasing action is...

The movement of the eye as it focuses on details of a scene. Some imaging systems mimic this movement by small, rapid scanning motions of the sensor.

Scalar diffraction theory is a simplified approach used to describe the propagation of electromagnetic waves, particularly light, as they encounter obstacles or apertures. It is termed "scalar"...

A camera that consists of a concave spherical mirror with an aspheric plate situated at the center of curvature of the mirror. The purpose of the plate is to correct the spherical aberration of the...

A specific type of photographic plate designed with only a small amount of gelatin to function in the extreme ultraviolet and in positive-ray analysis.

A scientific CMOS (complementary metal-oxide-semiconductor) camera is a type of digital camera specifically designed for scientific imaging applications. It employs CMOS sensor technology, which...

1. In glass, a solid inclusion having a small diameter. 2. A particular, single crystal that, after undergoing the Czochralski method, evolves into large single crystals.

A semiconductor is a type of material that has electrical conductivity between that of a conductor and an insulator. In other words, semiconductors have properties that are intermediate between...

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...

A handheld navigational instrument used to measure the elevation angle of celestial bodies such as the sun. An image of the sun is viewed through a small telescope via two plane mirrors so that any...

The Shack-Hartmann wavefront sensor is an optical device used for measuring the wavefront aberrations of an optical system. It is widely used in adaptive optics systems to correct distortions and...

A term used to denote a concave surface having too long a radius of curvature. That is, its negative power is too small or low.

An interferometer in which interference is produced between wavefronts that are sheared in the sample object by a small lateral distance.