Photonics Dictionary

The optical process, following grinding, that puts a highly finished, smooth and apparently amorphous surface on a lens or a mirror.

Polymers are large molecules composed of repeating structural units called monomers. These monomers are chemically bonded together to form long chains or networks, creating a macromolecular...

A thermoplastic, self-extinguishing polymer with excellent high-temperature, low-creep and arc resistance properties.

A crystalline material with a high electro-optic coefficient, capable of operating at short wavelengths, with applications in laser, optical disc, printing and microwave systems.

A laser with a gain medium consisting of an organic dye, which is carbon-based. The dye is mixed with a solvent, allowing the molecules to diffuse evenly throughout the liquid. The dye medium is...

A pump laser is a type of laser used to provide the necessary energy to the gain medium of another laser or laser system, initiating the process of stimulated emission and producing laser light. The...

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 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...

Quantum dot light-emitting diode (QLED) is a display technology that utilizes quantum dots, which are semiconductor nanocrystals, to produce vibrant and high-quality images. QLED displays are...

Quantum dot thin films refer to thin layers or coatings composed of quantum dots deposited onto a substrate surface. Quantum dots are nanoscale semiconductor particles typically ranging from a few to...

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...

The quarter video graphics array (QVGA) is a display resolution standard used in video graphics, particularly in LCD displays, digital cameras, mobile phones, and other portable electronic devices....

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 read-out integrated circuit (ROIC) is an electronic device used in imaging systems, particularly in infrared (IR) and other sensing technologies. It is designed to interface with an array of...

A reconfigurable optical add-drop multiplexer (ROADM) is a key component in wavelength-division multiplexing (WDM) optical communication networks. It allows for flexible and dynamic routing of...

The term reflective is an adjective that describes the ability of a surface or material to reflect light or other forms of radiation. It implies the capability of bouncing back or redirecting...

A resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or stimulus is applied at a specific frequency, causing the system to oscillate...

The retina is a light-sensitive tissue layer located at the back of the eye, opposite the lens. It plays a crucial role in the process of vision by converting light into neural signals that are sent...

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...

A Rugate filter is a type of optical filter that is designed to have a continuously varying refractive index profile throughout its thickness, rather than the discrete layers found in traditional...

The term "Rydberg atom" refers to an atom in a highly excited state where one or more of its electrons are in a Rydberg orbital. A Rydberg atom is characterized by having an electron orbit that is...

Sapphire crystal refers to a transparent, single-crystal form of aluminum oxide (Al2O3) known as corundum. It is one of the hardest known materials, second only to diamond on the Mohs scale of...

Sapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide (Al2O3) that is highly transparent in the infrared region of the electromagnetic...

A sapphire window refers to a transparent optical component made from sapphire crystal. Sapphire is a single-crystal form of aluminum oxide (Al2O3) that is highly prized for its exceptional optical...

Sapphire refers to a crystalline form of aluminum oxide (Al2O3) that is used in various optical and photonic applications due to its exceptional optical, mechanical, and thermal properties. Sapphire...

Scanning electron microscopy (SEM) is an advanced imaging technique used in microscopy to obtain high-resolution, three-dimensional images of the surfaces of solid specimens. SEM achieves this by...

Schrödinger's cat is a thought experiment devised by the physicist Erwin Schrödinger in 1935 to illustrate the paradoxical nature of quantum mechanics, particularly the concept of...

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...

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...

Selective laser melting (SLM) is an additive manufacturing (AM) or 3D printing technology that belongs to the powder bed fusion category. SLM is primarily used for metal additive manufacturing, where...

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...

Silicon carbide (SiC) light-emitting diodes (LEDs) are semiconductor devices that emit light when an electric current is applied to them. These LEDs are made using silicon carbide as the...

A silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector specifically designed for detecting and measuring light intensity. Silicon...

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...

Referred to as SWCNTs, these cylindrical nanostructures composed of a folded sheet of graphene can be used as near-infrared markers for small animal multiplex imaging. Emitting at different...

A singlet lens is an optical lens made from a single piece of material, typically glass or plastic, with one or both surfaces being spherical or aspherical. It is the most basic type of lens used in...

An instrument used for viewing in low levels of illumination by means of infrared radiation. A high-aperture lens forms an image of distant objects on the photocathode of an infrared-sensitive image...

Spatial light interference microscopy (SLIM) is an optical microscopy technique that belongs to the category of quantitative phase imaging methods. It is designed to provide high-resolution,...

A technique for obtaining improved resolution of images produced by large telescopes and distorted by the effects of atmospheric turbulence. Many individual exposures are recorded at high speeds by a...

Spectral domain optical coherence tomography is an imaging technique used in medical diagnostics, particularly in ophthalmology, to visualize and analyze the internal structures of biological...

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...

A wavelength region of relatively high transmittance, surrounded by regions of low transmittance.

Spin coating is a widely used technique in the fabrication of thin films and coatings, particularly in microelectronics, optoelectronics, and nanotechnology. It involves depositing a liquid precursor...