Photonics Dictionary: O

Off-axis paraboloid and ellipsoid mirrors are specialized optical components used in various optical systems, particularly in applications requiring precise focusing, collimation, or imaging of...

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...

A monolithic device containing both photonic and electronic sources, detectors, modulators, etc., on a single semiconductor substrate.

The physical length of the light path in a substance divided by the refractive index of that substance. See also equivalent air path.

The figure seen through or imaged by an optical system. It may contain structures, natural or artificial, or it may be the real or virtual image of an object formed by another optical system. In...

The distance between the object and the cornea, or the first surface of the objective in an optical device.

The optical element that receives light from the object and forms the first or primary image in telescopes and microscopes. In cameras, the image produced by the objective is the final image. In...

A hemispherical covering that is rotatable about a central axis. There is a slit opening along one side wide enough to allow a telescope to be directed at any vertical angle up to 90°.

An electro-optical infrared tracker consisting of a beamsplitter, an illuminating source, an image dissector tube and an electronics unit, that automatically acquires and tracks particular eye...

A form of high-power microscope objective where the space between the object and the first element is filled with an oil having the same index as that element. This form reduces losses, increases the...

Oleophobic is a term used to describe substances or materials that repel or resist oils. The word oleophobic comes from the Greek words "oleo," meaning oil, and "phobos," meaning fear. Oleophobic...

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...

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...

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...

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 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 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...

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.

The imaginary line passing through both the centers of curvatures of the optical surfaces of a lens or mirror; the optical centerline for all the centers of an optical element(s) of an optical...

An optical barcode reader, commonly known as a barcode scanner, is a device that uses optical technology to capture and interpret data encoded in barcode symbols. Barcodes are typically printed on...

Directing an optical beam in varying directions by varying reflection, refraction, focusing and diffraction methods.

The phenomenon that can render an optical resonator the equivalent of a semiconductor flip-flop. A bistable device will remain stable in two optical states, one of high transmission and another of...

A casting consisting of an optical material molded into the desired geometry for grinding, polishing or, in the case of optical waveguides, drawing to the final optical-mechanical specifications.

A device for measuring linear dimensions. The optical caliper generally consists of two circularly mounted mirrors whose angular positions are monitored by an autocollimator, and that are capable of...

The use of retroreflective projection technology (RPT) to project a background image onto a masked object, such as a vehicle or overcoat, thereby making the masked object appear invisible....

Optical cements and adhesives are specialized materials used in the assembly and bonding of optical components in optical systems. These materials are designed to provide secure and durable bonds...

An optical channel monitor (OCM) is a device used in optical communication systems to monitor and analyze the performance of individual channels within a wavelength-division multiplexing (WDM)...

Optical character recognition (OCR) is a technology that is used to convert printed or handwritten text into machine-readable text. OCR software and systems are designed to recognize and extract...

An optical clock is a highly precise and advanced timekeeping device that relies on the oscillations of electromagnetic radiation in the optical or ultraviolet part of the electromagnetic spectrum....

Optical coatings are thin layers of materials applied to optical components, such as lenses, mirrors, filters, and prisms, to modify their reflective and transmissive properties. These coatings are...

Optical coherence tomography (OCT) is an imaging technique used in medical diagnostics and biomedical research to obtain high-resolution, cross-sectional images of biological tissues. An OCT imaging...

An optical combiner, in the context of optics and display technologies, refers to a device or component that combines multiple optical signals or images into a single output. The purpose of an...

Optical design and engineering services involve the development, customization, and optimization of optical systems and components to meet specific performance requirements and application needs....

Optical design software refers to specialized computer programs used by optical engineers, physicists, and designers to simulate, model, analyze, and optimize the performance of optical systems and...

1. A lens formed to a desired curve and used to form a polisher. 2. A piece of glass included in a block to fill out the area.

An optical part constructed of a single piece of optical material. It is usually a single lens, prism or mirror.

Optical fiber optic switches are devices used in optical fiber communication systems to selectively route optical signals from one input fiber to one or more output fibers. They play a crucial role...

Optical fiber is a thin, flexible, transparent strand or filament made of glass or plastic used for transmitting light signals over long distances with minimal loss of signal quality. It serves as a...