Photonics Dictionary: U

Clear All Filters x

table x

U x

unstable resonator

A resonator often used for mode control in Fresnel number laser cavities that is highly vulnerable to extremely weak external sources of feedback.

uhlbricht sphere -> integrating sphere

A hollow sphere coated internally with a white diffusing material and provided with openings for incident beam, specimen and detector used for measuring the diffuse reflectance or transmittance of...

ultrafast pulsed laser

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 fiber optics

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...

umbra -> penumbra

A source of light will not cast a distinct shadow of an interfering, opaque object, but will cast a shadow having two parts: 1. the umbra, or the central, totally dark part of the shadow; and 2. the...

underwater television system

A television system designed to obtain pictures of objects or scenes beneath the surface of the water. Generally, a low-light-level television camera and a suitable light source are enclosed in a...

unijunction transistor

A three-terminal semiconductor having only one PN junction and a stable, open-circuit, negative-resistance property.

unit plane -> principal plane

In a lens or lens system, that surface at which the projections of an entering and exiting ray intersect. Also known as the equivalent refracting surface, the principal plane is most often not...

Photonics DictionaryU

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)

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.