Photonics Dictionary

A Peltier cooler, also known as a thermoelectric cooler (TEC) or thermoelectric module, is a solid-state device that uses the Peltier effect to transfer heat between two electrical junctions. It can...

An erasable data recording and storage medium that uses a laser to heat the crystalline surface of the disc to a certain temperature, at which it becomes amorphous and records a bit of information;...

The current that flows through a photosensitive device, such as a photodiode, as the result of exposure to radiant power.

Photoluminescence is a phenomenon in which a material absorbs photons (light) at one wavelength and then re-emits photons at a longer wavelength. This process occurs when electrons in the material...

A photonic integrated circuit (PIC) is a compact and integrated device that incorporates multiple photonic components and functions on a single chip, similar to the way electronic integrated circuits...

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...

Optical fiber channel characterization scheme based on three assumptions; the discrete mode spectrum can be replaced by a continuum; the loss due to coupling between guided and radiation modes...

Power modulation refers to the intentional variation of power levels in a signal, often in the context of electronic communication systems. This modulation technique is used to encode information...

The use of variations in the power supplied to a laser to change the shape of the output pulse. The technique is used in laser welding, for example, to condition a surface by preheating it at a low...

Q-switched operation, or q-switching, is a technique used in lasers to produce short and intense pulses of light. The term "Q" in q-switching stands for "quality factor," which is a measure of 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...

A laser that generates a succession of pulses at a high enough repetition rate to appear continuous. The pump source is switched on for short intervals, nominally equal to the lifetime of the...

The time rate of flow of radiant energy, expressed in watts (W), and carries the units of Joule per second (J/s). The prefix often is dropped and the term "power" used.

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....

Optical glasses containing the oxides of rare earths such as lanthanum to impart a very high refractive index combined with a low dispersive power.

Ray tracing is a rendering technique used in computer graphics to simulate the way light interacts with objects in a scene. It involves tracing the path of rays of light as they travel through a...

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 low-power magnifier that usually has a large diameter.

Parametric measurement for elliptical fiber and cable expressed as a ratio of the two-directional flow of power through the cable at any chosen point.

Reflectance spectroscopy is a technique used to analyze the reflective properties of materials across various wavelengths of the electromagnetic spectrum. By measuring the reflectance of light from a...

Remote inspection refers to the process of inspecting, evaluating, or monitoring assets, equipment, infrastructure, or systems from a distance, typically using remote sensing technologies and...

Ability of a laser to resist variations in output power caused when it is slowly rotated about its optical or symmetrical axis.

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 scanning electron microscope (SEM) is a powerful imaging instrument used in scientific research, materials characterization, and various industrial applications. Unlike traditional 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...

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

Noise generated in the flow of current in the photomultiplier, produced by the intentional or controlled application of optical power to the photocathode.

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...

Single-molecule Förster resonance energy transfer (smFRET) is a specialized technique in biophysics and molecular biology used to study the distances and dynamic interactions between two...

Sputtering equipment is machinery used in the process of physical vapor deposition (PVD), specifically sputtering. Sputtering is a method of depositing thin films of material onto a substrate surface...

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

Stochastic optical reconstruction microscopy (STORM) is a superresolution microscopy technique that enables imaging of biological specimens at resolutions beyond the diffraction limit of conventional...

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...

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 telescope that produces an erect image. Erection is achieved either by a lens (for a long instrument) or a prism (for a compact instrument). Very small terrestrial telescopes of low power may be of...

Time-lapse optical coherence tomography (OCT) refers to a medical imaging technique that captures a series of sequential OCT scans over time, allowing for the dynamic observation and monitoring of...

Tip-enhanced Raman scattering (TERS) is a powerful technique that combines Raman spectroscopy with the enhanced spatial resolution provided by a sharp metallic or dielectric tip. TERS allows...

The laser pumping that exhibits an advantage over longitudinal pumping in that the threshold pump power density can be lowered approximately in proportion to the laser length.

Abbreviated TEA CO2 laser. A gas laser that provides shorter pulses and higher peak powers than conventional CO2 lasers. The electrical excitation pulse occurs transversely to the optical axis...

An ultrafast pulsed laser is a type of laser that emits extremely short pulses of light with durations typically on the order of femtoseconds (10-15 seconds) or picoseconds (10-12 seconds). These...

A multilayer antireflective thin-film coating, so called because its reflectance rises steeply at wavelengths above and below a narrow band at zero. The v-coat is particularly useful in high-power...

An Abbe condenser in which the upper lens element is fixed. The lower lens may focus the illumination between the elements so that it emerges from the fixed lens as a large-diameter parallel bundle....