Photonics Dictionary: V

A method of spectral analysis using wavelengths between 100 and 300 nm that utilizes both emission and absorption techniques.

A scanning technique in which the optical density of the film being scanned controls the speed of deflection of the scanning beam.

A method of measuring negatively charged phase ions using a color-center or lead-salt diode laser.

A device that changes the number of lines per frame of a video image to adapt to a lower resolution format, either by deleting lines, compressing lines or by imaging only a part of the original...

The observation of specimens by a microscope linked to a television camera and an image processor.

A disc whose surface contains recorded digital data at high-packing densities arranged in concentric rings. The data, representing video frames, are both recorded and read by a laser beam.

A vacuum chamber is a sealed enclosure from which air and other gases are removed to create a low-pressure environment, typically close to or at a complete vacuum. These chambers are often...

The technique of producing spectrograms in wavelengths beyond 120 nm by the use of a diffraction grating and a Schumann plate in a vacuum environment.

Short-distance scattering of light in holography caused by random index inhomogeneities and the developing index that interferes with the incident beam, thus recording a hologram of the scattered...

With respect to microscopy, light that is directed down through the objective onto the specimen and then returned by reflection.

With respect to microscopy, light that is directed through the specimen by a substage condenser.

Two electrodes that shift the electron beam vertically on a cathode-ray tube screen using electrostatic deflection.

Consists of a pair of radio telescopes concentrated on a single celestial object. This technique creates a single radio telescope with a diameter equal to the distance between the pair, which allows...

An image with variations in density due to the differential scattering ability of microscopic bubbles in a transparent layer.

A vibrational transition refers to a change in the vibrational energy of a molecule. Molecules consist of atoms that are connected by chemical bonds, and these atoms are not stationary but are in...

Referring to the bandwidth and spectrum location of the signal produced by television or radar scanning.

A device that calibrates the size, position or distance of objects imaged on a video screen.

A device, optical or electronic, that may be joined to a camera so that the operator may perceive the scene as the camera does.

Virtual histology refers to the use of digital technology and computational methods to simulate or recreate histological images and structures without the need for traditional physical slides and...

An image that is formed when rays emerging from an optical system are diverging from the optical axis. The virtual image is formed where the bundle of diverging rays appear to intersect each other...

Virtual reality (VR) is a computer-generated simulation of a three-dimensional environment or experience that can be interacted with and explored by an individual using electronic devices, such as a...

The use of miniature scanners to project raster-scanned video images directly onto the surface of the human retina, eliminating the need for a projection surface.

A pair of stars (double star) that can be seen separately with a telescope, generally by setting a filar micrometer for the separation and position angle. Observation of visual binaries improves with...

An electron tube that stores and visually displays information by means of a cathode-ray-beam-scanning and charge-storage mechanism.

A nondestructive testing method for very large scale integration circuits, using a scanning electron microscope to monitor changes in the electronic state of the chip as it is fed test voltages while...

Volume Bragg gratings (VBGs) are specialized optical elements that consist of periodic variations in refractive index throughout the volume of a transparent material, typically a photosensitive glass...

Volumetric imaging refers to the capture, visualization, and analysis of three-dimensional (3D) information from a volume of space. Unlike traditional two-dimensional (2D) imaging, which provides...

A vortex phase plate is an optical device designed to impart a phase singularity, commonly referred to as a vortex or phase vortex, onto a light beam. This singularity results in a phase profile...