Photonics Dictionary: W

A system used for gratings that consists of a concave mirror, a grating and a plate holder mounted normal to the grating to reduce astigmatism and spherical aberration. The mounting yields a...

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.

In quantum mechanics, a wave function (often denoted by the Greek letter Ψ, psi) is a mathematical description that represents the quantum state of a particle or a system of particles. It...

The continuous group of waves that persists for a short time only.

A waveform is a graphical representation of the shape and magnitude of a signal over time. It typically depicts how the amplitude (strength) of the signal changes over time, with time plotted along...

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 photofluorescent compound that, when used with a scintillating substance, absorbs photons and emits related photons having a greater wavelength. In this way a phototube or photocell may employ the...

A photometer that uses a wedge, marked to show its reduction of flux density, to make two light sources equal in intensity for comparison of luminous intensities. This is accomplished by the gradual...

A diffraction pattern sampling unit composed of a 32-element monolithic silicon photodiode array and a readout unit. The intensity on each detector element can be separately read out by means of a...

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

An optical element having plane-inclined surfaces. Usually the faces are inclined toward one another at very small angles. Wedges divert light toward their thicker portions, and may be circular,...

Also known as cathode-ray tube grid or shield. A cylindrically shaped electrode that, containing the cathode of a cathode-ray tube with opposite potential, is designed to focus and control the...

The Weissenberg method, named after the German physicist Karl Weissenberg, is a technique used in x-ray crystallography for obtaining high-quality diffraction patterns from single crystals. This...

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...

Whispering gallery mode (WGM) refers to a phenomenon in wave physics, particularly in optics, where waves, such as light or sound waves, are trapped and circulate along the periphery of a curved...

Light perceived as achromatic, that is, without hue.

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 common aberration in lenses covering large fields of view; it results in images of objects near the edge of the field being compressed in the radial distortion.

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...

After putting a thick photographic emulsion on a front-faced mirror, and exposing the emulsion to monochromatic incident light normal to the face, Wiener discovered, upon developing the emulsion,...

A method that embraces the classical approach to image restoration and attempts to minimize the mean square difference between the original ungraded signal and the restoration.

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

A polarizing prism consisting of two calcite prisms cemented such that they deviate the two emerging beams (which are mutually perpendicularly polarized) by nearly equal amounts in opposite...

A type of radial gradient lens that can focus light even though its surfaces are flat.

The maximum aperture of a lens at which it will still give a sharp image, even though its physical aperture may be larger.