Photonics Dictionary: O

A common technique in microscopy, oblique illumination is one in which the object is illuminated by a light source that is at an oblique angle (on the side) to the optical axis. This technique is...

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 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 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 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...

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,...

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 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...

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....

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...

Also known as OCT-A, optical coherence tomography angiography is an imaging technique that uses light waves to measure changes in the reflectance characteristics, enabling the the quantitative...

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 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...

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...

In dry etching, a method of characterizing the composition of solid materials such as metal. Atoms in the OES technique are excited by energy that comes from a spark formed between the sample and an...

A device designed to measure linear or rotary motion by detection of the movement of markings on a transparent medium past a fixed point of light. The encoder has a moving code plate, a glass disc...

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...

An optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical filters are used to control the spectral content of light in various...

A piece of glass, pyrex or quartz having one or both surfaces carefully ground and polished plano, generally flat to less than a tenth of a wavelength. Optical flats are used in surface testing to...

The optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial domain representation of an image into its corresponding frequency domain...

Optical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems, such as lenses, prisms, mirrors, and filters. Optical glass is...

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...

In compact disc and CD-ROM technology, the portion of the drive that projects the laser light onto the surface of the media and picks up the resulting reflections read as data. The head includes the...

A device used to detect and measure small amounts of rotation. The rotating object contains a reflecting surface from which a beam of light is reflected onto a positional detector. A large distance...

Optical manufacturing tools and machinery encompass a wide range of equipment, instruments, and systems used in the fabrication, shaping, finishing, and testing of optical components and systems....

Optical materials refer to substances or compounds specifically chosen for their optical properties and used in the fabrication of optical components and systems. These materials are characterized by...

1. The direct storage of data as bits in memory using optical systems and properties. The memory makes use of a laser beam that is divided by a beamsplitter and controlled by a modulator and a...

Optical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or integrity of the transmitted information. This type of noise is particularly...

Optical phase distortion refers to a phenomenon where the phase of an optical wavefront is altered as it propagates through a medium. This distortion can result from variations in the refractive...

Also known as the Wiener spectrum or the noise power spectrum, the optical power spectrum is a fundamental quantity in film-screen image quality evaluation. It is a means of describing image content...

The determination of the temperature of a source by the detection of its incandescent brightness.

With respect to microscopy, also called dispersive staining, optical staining the projection of colors through areas of a colorless specimen by color filters that are constructed to fit over the...