Register
Sign In
Suppliers
Products
Categories
Handbook
Dictionary
Careers
Resources
Photonics Spectra
BioPhotonics
Vision Spectra
Virtual Events & Summits
Educational Institutions
Add/Update Your Listing
Exhibitor Listing Portal
Become an Exhibitor
Buyers' Guide Print Edition
Marketplace Help
Subscribe
Advertise
Suppliers
Products
Categories
Handbook
Dictionary
Careers
Resources
Photonics Spectra
BioPhotonics
Vision Spectra
Virtual Events & Summits
Educational Institutions
Add/Update Your Listing
Exhibitor Listing Portal
Become an Exhibitor
Buyers' Guide Print Edition
Marketplace Help
Register
Sign In
Photonics Marketplace
Suppliers
Products
Handbook
Institutions
Dictionary
Show Filters
Hide Filters
Type
Definitions
Abbreviations/Acronyms
Browse by Letter
#
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
30 terms
Photonics Dictionary: F
Clear All Filters x
focus x
F x
focus
1. The focal point. 2. To adjust the eyepiece or objective of a telescope so that the image is clearly seen by the observer. 3. To adjust the camera lens, plate, or film holder so that the image is...
focus control
1. A mechanism that permits the focusing of an optical system.2. A means of obtaining the sharpest image from a cathode-ray tube display by adjusting the size of the spot where it reaches the screen.
focus lamp
An incandescent or carbon arc lamp designed with a stable and compact arc or filament that permits it to be used as a light source to be focused by a lens system.
focused laser scattering
A single-particle scattering technique in which an incident laser beam is tightly focused by means of lenses to yield a focal spot in the scattering material with a diameter on the order of the...
focusing anode
One of the electrodes used to focus the electron beam of a cathode-ray tube. As the electrode's voltage is changed, its electrical field is changed, resulting in a change of the electron beam's spot...
focusing coil
A coil used to focus an electron beam by the generation of a magnetic field parallel to the beam.
focusing corner cube
A retroreflector that can focus a beam of light, with one planar reflective surface, one spherical and a third that is either planar or convex cylindrical.
focusing scale
A scale on an optical instrument that indicates the condition of focus. May indicate the distance to the object or diopter output, or from infinity focus.
fixed focus
Describes devices that are not provided with a means of focusing.
fixed-focus mode
->
convergent beam sensing mode
A type of photoelectric proximity mode sensing incorporating a lens system to focus the light from the emitter in a small, concentrated spot at a specific point in front of the sensor. Also referred...
front-cell focusing
A method of focusing an optical system by moving the front component (the lens closest to the subject) to change the distances between components. Also known as front-element focusing.
f-Theta lens
An f-theta lens, also known as an f-theta scan lens or simply an f-theta lens system, is a specialized optical component used in laser scanning systems, particularly in laser marking, engraving, and...
far point (of vision)
The object distance at which the eye is focused with the eye lens in a neutral or relaxed state.
FIB
focused ion beam
fiber-coupled LED
A fiber-coupled LED (light-emitting diode) refers to an LED device that is optically coupled to an optical fiber for the purpose of efficient light transmission. In this configuration, the LED serves...
filovirus
Filoviruses are a family of viruses that are responsible for severe and often fatal hemorrhagic fevers in humans and non-human primates. The name "filovirus" is derived from their filamentous...
fingerprint camera
A fixed-focus camera designed to record the ink impression of fingerprints that have been impressed on a card or form for record purposes.
flat-field lens
A lens that focuses on a flat plane because its field of curvature is close to zero.
FLLS
focused laser lithographic system
fluorescence correlation spectroscopy
Fluorescence correlation spectroscopy (FCS) is a powerful analytical technique used to study the dynamics and interactions of fluorescently labeled molecules in solution at the single-molecule level....
fluorescence lifetime imaging
Fluorescence lifetime imaging (FLIM) is an advanced imaging technique that provides information about the lifetime of fluorescence emissions from fluorophores within a sample. Unlike traditional...
focal length
The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...
focal plane array
A linear or two-dimensional matrix of individual detector elements, typically used at the focus of an imaging system.
focal power
In a symmetrical optical system this is a measure of the influence of the system upon the focus of a pencil of rays passing through it.
free-electron laser
A free-electron laser (FEL) is a type of laser that generates coherent, high-intensity electromagnetic radiation by using a beam of accelerated electrons as the lasing medium. Unlike traditional...
free-space optical interconnect
A type of internal photonic connection in an integrated circuit in which a holographic grating is used to focus light at points on a silicon chip, maximizing the speed of signal propagation.
Fresnel lens
A Fresnel lens is a type of optical lens that consists of a series of concentric grooves or steps carved into a flat, thin piece of transparent material, typically plastic or glass. This design...
Fresnel zone plate
A zone plate in which the zones are alternately transparent and opaque to specific radiation, and coarse enough so that no appreciable diffraction or focusing takes place. The Fresnel zone plate is...
front focal length
->
focal length
The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...
front operating aperture
The restricting aperture located at the front of the lens. It is usually defined as the maximum diameter of the entrance cone at the front vertex, for the specified field of view at infinity focus.
Photonics Dictionary
F
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.