Photonics Dictionary

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 crystal-based device that combines and adjusts the intensities of multiple wavelengths of laser light in order to obtain the desired output wavelength.

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.

Laws that predict the maximum power output as a function of tube diameter for a hydrogen cyanide laser of a given discharge length and cavity losses, all other parameters being optimized.

Acronym for profile resolution obtained by excitation. In its simplest form, probe involves the overlap of two counter-propagating laser pulses of appropriate wavelength, such that one pulse...

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 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...

A quantum well is a structure in quantum mechanics that confines particles, such as electrons or holes, in one spatial dimension. This confinement leads to quantized energy levels, creating a...

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...

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....

The radiation emitted in semiconductors when electrons in the conduction band recombine with holes in the valence band. If population inversion occurs between portions of the valence and conduction...

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...

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...

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...

A nonlinear label-free imaging technique commonly used during surgical procedures for the visualization of collagen fibers and muscle tissue (myosin) with submillimeter resolution. During the...

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...

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...

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...

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 laser whose output is limited to a single wavelength.

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...

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of light in two dimensions, typically in the form of an array. SLMs are...

Spatially offset Raman spectroscopy (SORS) is a technique that extends traditional Raman spectroscopy by incorporating measurements at different spatial offsets. This method allows for the selective...

Spectral flow cytometry is an advanced flow cytometry technique that expands the capabilities of traditional flow cytometry by utilizing spectral information from fluorochromes to enhance...

A spheric lens, also known as a spherical lens, is a type of optical lens with at least one surface that is part of a sphere. This means that the lens surface is curved in a symmetrical manner,...

A semiconductor laser that operates in the infrared and that is pumped with strong pulses of radiation from a second laser. Dependent on quantum-mechanical principles, it can be tuned over a large...

A type of laser used when a great amount of power is required. Avoiding the bulk of large numbers of optical lenses, this instrument offers high-output intensity and a small emitting region at...

STED microscopy, or stimulated emission depletion microscopy, is a superresolution imaging technique in fluorescence microscopy that surpasses the diffraction limit, enabling the visualization of...

A streak camera is a specialized instrument used to capture and analyze ultrafast phenomena, such as extremely short pulses of light or rapidly changing events. Unlike traditional cameras that...

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...

Instruments used for measuring angles and occasionally lengths on the ground. The principal surveying instruments are the level, the stadia telescope, the transit and the theodolite. Laser...

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...

The technique of generating ultrashort -- down to subpicosecond -- pulses by pumping a dye laser with mode-locked laser pumps with cavity lengths the same as, or a submultiple of, that of the dye...

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),...

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 Ti:sapphire laser is a type of solid-state laser that utilizes a titanium-doped sapphire crystal as the gain medium. The name Ti:sapphire comes from the combination of titanium (Ti) as the dopant...