Photonics Dictionary

With respect to television, the returning direction of the electron beam during the vertical blanking period.

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

A vertical-cavity surface-emitting laser (VCSEL) is a type of semiconductor laser diode that emits light vertically from the surface of a semiconductor wafer. VCSELs are commonly used in various...

Vibrational circular dichroism (VCD) is a spectroscopic technique used to probe the chiral properties of molecules. It measures differences in the absorption of left- and right-circularly polarized...

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.

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

Videography refers to the process of capturing moving images and recording them in a digital format. It involves the use of video cameras, lighting equipment, and audio recording devices to create...

A camera that permits adjustments in the perspective of an image; this is accomplished by the camera design, which permits tilt, swing, rise or fall of the image transmitted. Also known as a...

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...

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...

That term pertaining to the spectral region that can be perceived by the eye.

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...

In the context of electronics and semiconductor manufacturing, a wafer refers to a thin, flat disk or substrate made of a semiconducting material, usually crystalline silicon. Wafers serve as the...

An image intensifier tube in which the photocathode and the output of the microchannel plate are proximity-focused on the microchannel plate input and output phosphor screen, respectively.

1. An undulation or vibration; a form of movement by which all radiant energy of the electromagnetic spectrum is estimated to travel. 2. A type of surface defect, usually due to improper polishing.

A wavefront refers to the continuous surface or boundary representing points in a wave that are in phase, meaning they have the same phase or position in their respective cycles. In simpler terms,...

A waveguide is a physical structure or device that is designed to confine and guide electromagnetic waves, such as radio waves, microwaves, or light waves. It is commonly used in communication...

A method of specifying the allowable edge-thickness difference or decentering of a lens.

A statistical means of characterizing the failure of a fiber or device as related to strain or time. Results are plotted on a special graph paper to yield the distribution shape parameter.

A well plate, also known as a microplate or microtiter plate, is a flat plate with multiple small wells or depressions arranged in a grid pattern. Each well serves as a separate container for holding...

The random noise having a spectral density that is substantially independent of the frequency over a specified frequency range. White noise is widely used in the random vibration testing of devices.

An extremely wide emission spectrum generated by the nonlinear effects created when a high peak power from a short-pulse laser is focused into a water or carbon tetrachloride cell. The resulting...

The theorem stating that, when the sampling period in a recorded sample hologram is matched to the object spectrum, the resulting image does not suffer any loss of information content.

Whole slide imaging (WSI), also known as virtual slide microscopy or digital pathology, is a technology that involves the digitalization of entire glass slides containing histological or cytological...

A wide-angle lens is a type of camera lens that has a shorter focal length than a standard or normal lens, allowing it to capture a broader field of view. Wide-angle lenses are characterized by their...

Wide-field fluorescence microscopy uses either naturally occurring structures or staining with fluorescent tags that are activated by specific wavelengths of light and then emits a different...

The formula that gives the wavelength of maximum spectral radiant emittance of a perfect blackbody: λmax = 2898/T(µm) The radiation at this λmax can be calculated as follows:...

1. A piece of glass with plane parallel surfaces used to admit light into an optical system and to exclude dirt and moisture. 2. A particular region of the electromagnetic spectrum that has been...

Specified curved optic intended for maximum collection of light, including off-axis rays, before leaving the exit aperture.

In microscopy, the clear distance between the specimen being viewed and the first optical element of the objective lens.

X resolution is a measure of the number of pixels or data points along the horizontal axis of an image or display. It quantifies the level of detail that can be displayed horizontally, representing...

The study of the celestial bodies, relative to x-ray emission. Satellites launched to study x-ray sources have revealed many new classes of galactic and extragalactic sources, as well as the...

The collection and detection of x-rays by virtue of their ionizing properties. The ionization may be perceived directly by a gas-filled ionization chamber, photographically, or by correlating...

A method of projecting integrated circuit patterns on a silicon wafer using x-ray wavelengths focused through a special mask.

The method of acquiring characteristic x-ray spectra from microscopic samples by use of the combination of a scanning electron microscope and x-ray spectroscopy.

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...

Broadening of a spectrum that results from the influence of a magnetic field.

A highly flame-retardant material used to jacket fiber optic cables, especially on shipboard applications.