Photonics Dictionary

The arrangement of two Porro prisms so that the inverted image formed by certain types of optical instruments is the same as the object. The first prism, which is set at 90° to the second, inverts...

A prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent object with at least two flat surfaces that are inclined relative to each...

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 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...

1. An optical distance finder that depends on triangulation of two convergent beams on an object from disparate view points. 2. A device that depends on the measurement of time of wave travel from an...

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....

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 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 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 reticle, also known as a reticule or graticule, is a pattern or set of markings placed in the focal plane of an optical instrument, such as a microscope, telescope, riflescope, or camera, to...

Retroreflection is a phenomenon in optics where light is reflected back toward its source, typically in a direction nearly parallel to the direction from which it originated. This occurs due to the...

A retroreflector is an optical device or structure that reflects incident light or electromagnetic waves back to their source, regardless of the direction from which the light approaches. Unlike...

A reflecting prism that is rhomboidal in shape. It has two parallel transmitting faces, and two parallel reflecting faces; the latter are oblique to the former (usually but not necessarily at...

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...

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...

An arrangement of optical fibers in a bundle whereby the geometric configuration of the input end differs from that of the output end without changing the total area; for example, a circular bundle...

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 crystal, glass, or quartz slicing and cutting machine is a specialized piece of equipment used in the manufacturing process to precisely cut and slice materials such as crystals, glass, and quartz...

Optical elements arranged with no spaces between, so that the light travels only through glass, not air.

A sputtering target is a solid material used in the process of physical vapor deposition (PVD), specifically sputtering. Sputtering targets are typically made of metals, metal alloys, or compounds...

Structural color refers to coloration in materials that is not caused by pigments or dyes but is instead a result of the physical structure of the material. In structural color, the interaction of...

Structured illumination microscopy (SIM) is an advanced optical imaging technique used in microscopy to enhance the resolution of images beyond the diffraction limit imposed by traditional light...

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...

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...

A telescope lens is a primary optical component of a telescope system that gathers and focuses light to form an image. It is typically a curved, transparent piece of glass or other optical material...

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 deposition is a process used to deposit a thin layer of material onto a substrate surface, typically ranging from nanometers to micrometers in thickness. These thin films are utilized in...

Also known as TEA laser. A coherent optical source with a wide wavelength range in the infrared, visible and ultraviolet that uses an electrical discharge transverse to (across) the optical axis to...

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...

Ultraviolet (UV) coatings are specialized optical coatings designed to operate in the ultraviolet region of the electromagnetic spectrum, typically ranging from 10 nm to 400 nm. These coatings are...

Ultraviolet (UV) fiber optics refers to optical fibers that are designed and optimized for the transmission of ultraviolet light, which is electromagnetic radiation with wavelengths shorter than...

A blank area (caused by insufficient inking of the paper) that falls within the range of an intended character stroke in an optical character-recognition system.

A YAG crystal refers to a solid-state crystal made of yttrium aluminum garnet (YAG), which is a synthetic crystalline material. YAG crystals are known for their exceptional optical properties,...

A ytterbium laser is a type of solid-state laser that employs ytterbium ions (Yb³+) as the dopant in the gain medium. These lasers are known for their high efficiency, broad absorption and...

Zerodur is a type of glass ceramic material known for its exceptional thermal and mechanical properties, particularly its low coefficient of thermal expansion (CTE) close to zero. It was developed by...