The Vision Spectra Conference is now available ON DEMAND: Discover emerging trends in Cameras, Systems, and Sensors!
Search
Menu
AdTech Ceramics - Ceramic Packages 1-24 LB
Photonics Marketplace
Suppliers Products
Handbook Institutions Dictionary

Show Filters
6,178 terms

Photonics Dictionary

Clear All Filters xTE x
radiant heat
Infrared radiation emitted from a source that is not heated sufficiently to give off visible radiation.
radiant power
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.
radiant reflectance -> reflectance
The ratio of reflected flux to incident flux. Unless otherwise specified, the total reflectance is meant; it is sometimes convenient to divide this into the sum of the specular and the diffuse...
radiation angle
Half the vertex angle of the cone of light emitted by a fiber.
radiation dosimetry
The detection and measurement of nuclear and x-ray radiation.
radiation length
The average length in a specific material in which a relativistic charged particle will lose 67 percent of its energy by bremsstrahlung.
radiation mode
A mode in an optical waveguide whose fields are transversely oscillatory everywhere external to the waveguide. It exists even in the limit of zero wavelength.
radiation pressure
The force exerted on a surface by radiation.
radiation thermocouple
A thermocouple that is used in infrared spectroscopy to detect a sample's infrared emittance. See thermocouple.
radiation trapping
That process by which radiation spontaneously emitted by a volume of optical materials is resonantly reabsorbed within the same volume before it escapes. This effect is manifested in a reduction in...
radiation-monitoring film
The film used in photographic dosimetry to record the types and amounts of ionizing radiation, such as x-rays and gamma rays, present in an area for a set interval of time. The negative produced by...
radiation-shielding windows
Plates of glass containing as many heavy metal oxides as can be dissolved in the glass without causing devitrification. The glass is yellow, very heavy and has a high refractive index. It is almost...
radiative recombination -> band-to-band photoluminescence
The emission of a photon by the return of an excited carrier from the conduction band to the valence band of a semiconductor along a radiative recombination path. The resulting photoluminescence...
radio astronomy
The detection and analysis of naturally formed extraterrestrial electromagnetic radiation within the radio frequency range of the spectrum.
radio frequency
The frequency range for radio and television transmission.
radio-frequency discharge laser
A gas laser in which the electrodes are mounted perpendicular to the optical resonator.
radio-frequency light source
A very uncommon lamp in which a tungsten electrode is heated to incandescence by a radio-frequency electrical current.
radio-frequency linear accelerator
A device used to accelerate the electrons in a free-electron laser by channeling microwave energy into waveguide cavity assemblies.
radioactive tracer
A radioactive element that is placed or injected into a system to obtain an autoradiogram of the system. It is used in a number of fields where standard methods of internal imaging, for example,...
radioautograph
The photographic image of a thin specimen having a radioactive isotope that, formed through contact between the specimen and a photographic plate, displays the distribution of the radioactive...
radiograph
An x-ray or radium photograph illustrating the nonuniform density of the structure that the rays penetrate.
radiographic amplifier screen
A solid-state panel of the photoconductor-electroluminescent type. The photoconductive layer, sensitive to x-rays, is coated by the electroluminescent, which gives the visible image. When the former...
radiography
A photographic process using x-ray radiation or the g-rays of radioactive materials.
radiopaque
Incapable of being penetrated by any form of radiation.
radioparent
Capable of being penetrated by some form of radiation.
radiophotograph
A photograph transmitted by radio waves.
radiophotoluminescence
The luminescence displayed when particular minerals are irradiated with β-rays and g-rays, after being exposed to nuclear radiation.
radius tool
A metal device of convex or concave curvature to which lens castings or semifinished lenses are cemented with only their edges in contact with the device.
radiuscope
A microscope to which a beamsplitter and illuminated reticle have been added that is used to measure contact lenses.
radix
Total number of characters available to each position of a digital numeric system.
RAI
random access integration
rail -> optical bench
A support for optical parts comprising a solid bed that permits precise longitudinal movement of one component relative to the others, and a number of sliders equipped with holders for lenses, lamps,...
rainbow hologram
Essentially, a hologram of a hologram, in which the first-generation hologram is masked with a narrow slit. During image reconstruction, the slit operates as the exit pupil in image space. The...
Raman fiber probe
A flexible fiber cable with a small diameter that transports light from the excitation laser to the target. Used in Raman spectroscopy, the probe is capable of obtaining high-quality data at high...
Raman spectroscopy
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...
Ramsden circle -> exit pupil
In a lens or other optical system, the image of the aperture stop as seen from image space.
random access multiphoton microscopy
Also known as RAMP microscopy, random access multiphoton microscopy is a microscopic technique that uses multiple acousto-optic modulators to enable faster and addressable scanning of 3D cellular...
random noise
Essentially, noise that cannot be predicted. Therefore, even if the magnitude of sound or oscillation in a system is known at a given moment, random noise can change in a short time.
randomized fiber optic cable
Fiber optic cable in which the arrangement of fibers within the bundle has been made random so that output light will be uniformly distributed and not relay the image of the light source at the input...
range axis
The third dimension (depth or Z-axis) in an imaging system.
rangefinder
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...
rapid rectilinear lens
A double meniscus system in which two achromatized meniscus lenses are arranged symmetrically on either side of the aperture stop, reducing or eliminating distortion, coma and lateral color.
rare earth dopants
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....
rare gas halide laser -> excimer laser
An excimer laser is a type of ultraviolet laser that emits short pulses of light in the ultraviolet spectrum. The term excimer is derived from excited dimer, reflecting the nature of the gain medium...
rare-earth doped fiber
An optical fiber in which ions of a rare-earth element, such as neodymium, erbium or holmium, have been incorporated into the glass core matrix, yielding high absorption with low loss in the visible...
rare-earth elements
Rare-earth elements (REEs) are a group of seventeen chemical elements found in the Earth's crust, characterized by their unique properties and scarcity relative to other elements. Despite their name,...
rarefaction
In a gas, the temporary drop in density caused by contact with a sound wave.
RAS
remote active spectrometer
ratiometry
Ratiometry is a technique used in various scientific fields, particularly in analytical chemistry and biochemistry, to measure concentrations or quantities by comparing the intensity of two different...
raw glass
A term that describes any state of glass before its manufacture as an element.

Photonics Dictionary

Marketplace Help Need Help?

Explore Our Content
News
Features
Latest Products
Webinars
White Papers
All Things Photonics Podcast
Videos
Our Summits & Conferences
Industry Events
Bookstore
Join Our Community
Subscribe
Advertise
Become a member
Sign in
Contribute a Feature
Suggest a Webinar
Submit a Press Release
Mobile Apps

About Us
Our Company
Our Publications
Contact Us
Career Opportunities
Teddi C. Laurin Scholarship

Terms & Conditions
Privacy Policy
California Consumer Privacy Act (CCPA)



©2024 Photonics Media
100 West St.
Pittsfield, MA, 01201 USA
[email protected]
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.