Photonics Dictionary: H

An optical test table made up of two outer layers or "skins'' bonded to either side of a honeycomblike core, usually of aluminum or steel. It results in equal quality with greatly reduced weight...

Also known as constant angle or constant deviation fringes. The interference fringes observed with dense flat plates near normal incidence. The fringes of the Fabry-Perot interferometer are Haidinger...

1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the screen's light being reflected by the front and rear surfaces of the tube's...

In chemistry, a halide refers to a chemical compound containing one or more halogen atoms bonded to another element. The halogens are a group of elements in the periodic table that includes fluorine...

A halogen lamp, also known as a tungsten halogen, quartz-halogen, or quartz iodine lamp, is an incandescent lamp that uses a tungsten filament surrounded by a small amount of halogen gas, such as...

An optical system that superimposes a synthetic display providing navigational or weapon-aiming information on a pilot's or driver's field of view. The system includes a cathode-ray tube, collimating...

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates based on the principle of stimulated emission of photons from excited helium...

Optical fiber in which the attenuation exceeds the normally acceptable level for long-haul or data communications use.

A camera designed to record at rates exceeding 50 fps. For frame rates up to about 500 fps, an ordinary pull-down mechanism can be used. From 500 to 1000 fps, the film must be moved continuously, the...

A fish-eye lens designed to photograph cloud formations over the entire visible sky.

A soft, malleable, stable rare-earth element. Holmium laser systems are used in surgical procedures involving the cutting and vaporizing of soft tissue, cartilage and calcific structures.

Holmium lasers are a type of medical laser that utilizes holmium-doped crystals as the gain medium. The term holmium laser is often associated with a specific type of laser used in urology for...

An interference pattern that is recorded on a high-resolution plate, the two interfering beams formed by a coherent beam from a laser and light scattered by an object. If after processing, the plate...

A holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to capture 3D holographic images of objects or scenes. Unlike conventional...

A holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists of a periodic structure of alternating transparent and opaque regions,...

Term applied to laser technology to denote an area of above-average intensity often attributable to atmospheric inconsistencies.

An ocular having two planoconvex lenses that are formed from similar glass and that are separated by a space equal to half the sum of their focal lengths. This eyepiece is free of lateral chromatic...

E.I. duPont's trade name for a material used in the jacket of fiber optic cables. It is flame-retardant, thermally stable and resistant to oxidation, ozone and radiation.

A hyperspectral imaging camera is a sophisticated imaging device capable of capturing and processing data across a wide range of wavelengths within the electromagnetic spectrum, typically from...