Photonics Dictionary

Lens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance, quality, and characteristics of lenses. These instruments are essential for...

Long-wave infrared (LWIR) refers to a specific range of the infrared spectrum. Infrared radiation is divided into three main categories based on wavelength: near-infrared (NIR), mid-wave infrared...

Luminescence is the emission of light that occurs without the involved substance undergoing a significant increase in temperature. In other words, it is the production and emission of light by a...

A magnon is a quasiparticle representing a quantized spin wave in a magnetic material. In other words, it is a collective excitation of the spins of electrons in a magnetic solid, analogous to the...

MWIR stands for mid-wave infrared, referring to a specific range of wavelengths within the infrared spectrum. Infrared radiation is categorized into three main regions based on wavelength:...

Modal bandwidth is a crucial parameter in optical fiber communication systems, particularly in multimode fiber (MMF) systems. It quantifies the ability of a fiber optic link to transmit data at high...

In optics, "mode beating" refers to an interference phenomenon that can occur in laser systems with multiple longitudinal modes. Longitudinal modes are specific electromagnetic field patterns that...

Modified chemical vapor deposition (MCVD) is a technique used in the fabrication of optical fibers. It is a specialized form of chemical vapor deposition (CVD) that is employed to produce...

A metal-semiconductor-metal (MSM) photodiode is a type of photodetector that consists of metal electrodes on a semiconductor material. Unlike the more common PIN photodiodes, which have a P-type and...

Multi-axis alignment refers to the process of aligning or adjusting components or systems in multiple spatial dimensions or axes. In various technical and engineering contexts, achieving precise...

A multiline laser system refers to a type of laser that is capable of emitting multiple discrete wavelengths or spectral lines simultaneously. Unlike single-line lasers, which produce radiation at a...

Nanophotonics is a branch of science and technology that explores the behavior of light on the nanometer scale, typically at dimensions smaller than the wavelength of light. It involves the study and...

A nanotube, also known as a nanotubule or simply a tube-like structure, is a nanoscale cylindrical structure composed of various materials, including carbon, boron nitride, or other compounds....

State typically studied in liquid crystals in which the dielectric coefficient parallel to the director is less than the dielectric coefficient perpendicular to the director.

The physical length of the light path in a substance divided by the refractive index of that substance. See also equivalent air path.

An otoscope is a medical device used by healthcare professionals, particularly ear, nose, and throat (ENT) specialists, primary care physicians, and pediatricians, to examine the ear canal and...

The term perovskite refers to a specific crystal structure commonly found in various materials. Perovskite structures have a cubic arrangement of oxygen ions, forming a framework within which other...

Phase matching is a crucial concept in the field of optics, particularly in nonlinear optics and the generation of coherent light. It refers to the condition where the phases of two or more waves,...

A quantum of electromagnetic energy of a single mode; i.e., a single wavelength, direction and polarization. As a unit of energy, each photon equals hn, h being Planck's constant and n, the frequency...

A photovoltaic cell, commonly known as a solar cell, is a semiconductor device that directly converts light energy into electrical energy through the photovoltaic effect. The photovoltaic effect is...

A PIN photodiode is a type of photodetector or semiconductor device used to convert light signals into electrical signals. The name "PIN" is derived from the arrangement of the three semiconductor...

The condition in which there are more atomic systems in the upper of two energy levels than in the lower, so stimulated emission will predominate over stimulated absorption. This condition may be...

Pyramid error in optics refers to an aberration in the shape of an optical surface, particularly in the context of mirrors. It is a type of distortion that can occur when the surface of a mirror...

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...

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics. It is a versatile and powerful device used for emitting coherent light in...

Quantum efficiency (QE) is a measure of the effectiveness with which a device or system, typically in the context of photonics or electronics, converts incoming photons (light) into a useful output...

Quantum entanglement is a phenomenon in quantum mechanics where two or more particles become correlated to such an extent that the state of one particle instantly influences the state of the...

Quantum key distribution (QKD) is a method of secure communication that utilizes principles from quantum mechanics to establish a shared secret key between two parties, typically referred to as Alice...

Rare earth dopants refer to elements from the lanthanide series, also known as rare earth elements, that are intentionally introduced into the crystal lattice of a material to modify its properties....

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...

Self-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a medium, causing a change in the phase of the light due to its interaction with...

Short wavelength infrared (SWIR) refers to the portion of the infrared spectrum that encompasses wavelengths roughly between 1,000 and 3,000 nanometers (nm). In the electromagnetic spectrum, infrared...

Spectral repeatability refers to the consistency and reproducibility of spectral measurements across multiple trials or instances. It is a measure of how well a measurement instrument or system can...

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,...

An instrument for measuring the radius of curvature of a spherical lens or mirror surface. It may consist of a ring resting on the surface, with a micrometer plunger in the middle of the ring to...

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...

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...

Total internal reflection fluorescence (TIRF) microscopy is an advanced fluorescence microscopy technique that leverages the principle of total internal reflection to selectively illuminate and image...