Photonics Dictionary

On-board optics refers to optical systems integrated into devices or platforms for various purposes, such as imaging, navigation, communication, and sensing. These systems are crucial in a wide range...

A glow discharge tube placed on an insulating rod to detect the presence of high-frequency radiation in the vicinity of a transmitter. The tube indicates the presence of the radiation by the glow...

An instrument for measuring opacity.

Opacity refers to the degree to which something is not transparent or translucent, meaning that it doesn't allow light to pass through it easily. It's a measure of how much a material obstructs the...

A material consisting of very small colorless particles imbedded in a clear glass matrix. It is available in two forms: flashed opal and pot opal. The flashed variety consists of a rather thin layer...

A tungsten filament lamp that uses an opal glass bulb to diffuse light.

A term describing a substance that is impervious to light; the characteristic of a substance that has no luminous transmittance.

An opaque projector is a device used for enlarging and projecting images from opaque objects such as printed pages, photographs, or three-dimensional objects onto a screen or surface. Unlike a...

A bubble at a polished surface that has been opened by grinding or polishing.

An interface in an optical network that permits an optical signal to pass without changing the optical signal to an electrical signal and therefore does not limit the signal to a specific protocol.

A measurement method for reflectance by gas ionization in which light passes through a vapor before and after reflection. Detection is accomplished with a phosphor-tipped lightpipe that leads to a...

In morphological image processing, a series of erosions followed by the same number of dilations.

Pertaining to the human eye.

A family of specialized instruments used by ophthalmologists and optometrists to study a patient's eyes and prescribe spectacles. It includes the ophthalmoscope to observe and photograph the retina;...

The methods and techniques used to obtain medical photographs of the human eye. To photograph the exterior of the eye, conventional still photographic equipment and procedures are used. Similarly, in...

Ophthalmology is a branch of medicine that focuses on the anatomy, physiology, and diseases of the eyes and visual system. Ophthalmologists are medical doctors who specialize in the diagnosis,...

See eye test apparatus; ophthalmic instruments.

Also referred to as a funduscope, an ophthalmoscope is a specialized instrument used by ophthalmologists for observing and photographing the fundus (interior) of the eye which includes the retina,...

Also referred to as fundus photography, ophthalmoscopy is the dioptrical study of the various interior components of the eye such as the macula, fovea, and opticdisk, and is overall essential in...

Also referred to as the opposition surge, the opposition effect is a photometric phenomenon in which a rough retroreflective surface appears brighter when illuminated from directly behind the...

The optic lobe refers to a specific part of the brain found in vertebrates and some invertebrates, particularly in the visual systems of these organisms. In vertebrates, including humans, the optic...

Pertaining to optics and the phenomena of light.

Optical aberration refers to imperfections or deviations from ideal optical behavior in an imaging system, such as a lens or a mirror. These aberrations can cause distortions, blurring, or other...

An optical accumulator is a concept or device that collects and stores optical energy or data for subsequent use. This can be applied in various fields within optics and photonics: Optical data...

The capacity of a chiral substance such as a crystal or molecule to rotate the plane of polarized light that is transmitted through it. Any substance that cannot be superimposed onto it's mirror...

A measure of the optical path length for light traveling from the sun or other celestial source through Earth's atmosphere to sea-level relative to the optical path length traveled by light from the...

The mathematical evaluation of an optical system to determine and quantify its basic optical properties and image quality characteristics.

Optical artifacts refer to undesired or unintended effects that can occur in optical systems, such as microscopes, cameras, telescopes, and other optical instruments. These artifacts can distort or...

An optical assembly refers to a collection of optical components that are carefully arranged and aligned to perform a specific function within an optical system. These components may include lenses,...

An instrument used to test lenses by utilizing the optical transfer function. It consists of a HeNe laser, a beamsplitter and two mirrors.