Photonics Dictionary: O

A coarse diffraction grating that is used to form a scale of intensities to determine the relative magnitudes of stars. The grating is placed over the objective of a telescope to form a diffraction...

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...

An instrument used to measure backscatter as well as optical return loss and reflectance within an optical fiber system by measuring the reflected light when a continuous wave is transmitted through...

A device for measuring diffraction grating efficiency at any angle of incidence, consisting of a reflectometer wherein the detector rotates around the grating at a specific distance and is attached...

An optical grating, in the context of optics and physics, refers to a device with a periodic structure of closely spaced, parallel slits or rulings. These slits or rulings act as obstacles to the...

Refers to a variety of methods and tools used to determine the surface contour and performance of optical components and systems.

An optical testing instrument is a device or system used to evaluate and measure the performance, quality, and characteristics of optical components, systems, and devices. These instruments play a...

A variable focal length lens system that retains the object in focus as one or more lenses move as a unit along its optical axis.

An organic light-emitting diode (OLED) is a type of light-emitting diode (LED) technology that utilizes organic compounds to produce light. OLEDs are commonly used in display technologies, such as...

In holography, the wave of light that illuminates the object to be recorded, which diffracts it to the recording medium, where it interferes with the reference beam, generating the hologram.

The movement of an object seen through a refracting prism toward the apex of a prism.

The physical adaption of the eye lens, by means of ciliary muscle contraction, in order to maintain a clear, in focus image of light and other objects and surroundings at a given distance onto the...

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...

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...

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 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...

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...

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;...

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,...

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...

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,...

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

A support for optical parts comprising a solid bed that permits precise longitudinal movement of one component relative to the others, and a number of sliders equipped with holders for lenses, lamps,...

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.

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....

A permanent, transparent, and highly transmissive adhesive capable of withstanding extreme temperatures that is applied to optical surfaces for the purpose of cementing, or the sticking together of...

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...

Transparent glassy and or crystalline structured materials engineered from inorganic, non-metallic materials via various methods that include heat or specific chemical reactions. Optical ceramics...

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...

A mechanical or electrical-electromagnetic device for periodically interrupting or blocking abeam of light for a brief known interval. The three most common chopper types include the tuning fork...

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 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...

Optical coherence tomography (OCT) is a non-invasive imaging technique used in medical and scientific fields to capture high-resolution, cross-sectional images of biological tissues. It provides...

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...

A system of modular mechanical components for building precision optical systems. The basic equipment includes a variety of modules for mounting, supporting and accurately positioning lenses and...

The adhesion of two sufficiently clean and close-fitting surfaces without the use of cement or glue. The optically contacted surface is almost as durable as the body of the glass, and the surfaces...

A device incorporating a spatial light modulator and a reference filter; used for matching an input optical waveform or signal with stored data in a photonic computer. This technique is done using...

The storage of information via optical means, primarily employing a low-power laser to inscribe data on a photosensitive surface as pits or phase differences and to read such data via reflected light...