Photonics Dictionary

A device for the internal inspection of hard-to-get-at mechanical parts, such as rifle barrels, sewer pipes, oil wells, or gas mains. The long narrow tube used contains a telescope system with as...

The law expressing the condition under which a crystal will reflect a beam of x-rays with the greatest amount of distinction or resolution and, at the same time, denoting the angle at which the...

A sheet of thin brass, one edge of which has been accurately cut to a known and marked circular radius. It is used to check the radius of curvature of a rough-ground lens by contact.

Brightfield refers to a type of microscopy and imaging technique in which the specimen is illuminated with a white light source, and the image is observed or captured against a bright background. In...

Broadband dielectric mirrors, also known as broadband mirrors, are optical coatings designed to efficiently reflect or transmit light over a broad range of wavelengths. These mirrors are constructed...

The process of lapping a thin edge of metal over the bevelled edge of a lens to maintain it within its cell.

A standard lens interface initially made for 16mm movie cameras and now used primarily on closed-circuit television cameras. It is a 1-in.-diameter, 32-thread-per-inch interface with a...

An optical material used in place of crown glass to produce lenses with extraordinary correction of chromatic aberrations. Its high coefficient of thermal expansion and its tendency to absorb...

A calcium indicator is a molecule that is sensitive to changes in calcium ion (Ca2+) concentrations in biological systems. These indicators are commonly used in various fields, including cell...

A forerunner of the modern camera, this instrument had a focusable lens that produced a sharp image on the enclosure opposite the aperture but had no photosensitive material to record it.

An apparatus, designed for use with a camera, that is used to rapidly open the path from lens to film, to maintain the opening throughout exposure and to close the opening in rapid succession. The...

A light-tight box that receives light from an object or scene and focuses it to form an image on a light-sensitive material or a detector. The camera generally contains a lens of variable aperture...

A gas laser in which the energy-state transitions between vibrational and rotational states of CO2 molecules give emission at long IR, about 10 µm, wavelengths. The laser can maintain...

A lens, one surface being a cartesian oval, that produces an aplanatic condition.

A system that uses both reflection and refraction to achieve its focal power. While the relative powers of the lenses and mirrors vary from system to system, the use of the reflective surfaces to...

Cathode radiant sensitivity refers to the ability of a photocathode to convert incident radiant energy, typically in the form of light, into an electrical signal. Photocathodes are components used in...

A fiber optic end plate constructed by drawing a bundle of parallel fibers embedded in glass and cutting it into thin slices. These slices are assembled in a plane and heated to produce a...

A high-quality, narrow-angle lens of high aperture designed for low magnification in the recording of cathode-ray tube images.

A CCD camera, or charge-coupled device camera, is a type of digital camera that utilizes a CCD image sensor to capture and record images. CCD cameras are widely used in various applications,...

A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images into electronic signals. It is a key component in digital cameras, camcorders,...

1. A single unit in a device for changing radiant energy to electrical energy or for controlling current flow in a circuit. 2. A single unit in a device whose resistance varies with radiant energy....

The surface of an element of a compound lens that will produce the cemented interface. The curves of this interface are called inside curves. To facilitate cementing, the two inside curves should...

1. Mounting a lens or mirror so that its optical axis is coincident with the optical or mechanical axes of other portions of the system. 2. The machining (edging) of the outside diameter of a lens...

In a perfectly centered lens, the mechanical axis (defined by the ground outside the diameter of the lens) is made to be exactly coincident with the optical axis (defined by a line through the...

A photoemissive detector sensitive to wavelengths up to 1 µm. It has one sharp maximum of sensitivity at 350 nm and a broad maximum at 800 nm.

Chalcogenide refers to a class of compounds containing elements from group 16 of the periodic table, which includes sulfur (S), selenium (Se), and tellurium (Te). These elements are known as...

A charge-coupled device (CCD) is a type of electronic image sensor used in various imaging devices, including digital cameras, camcorders, and scientific instruments. It consists of an integrated...

A chemical reaction involving the production of light. The reaction of ethylene with ozone is chemiluminescent.

Chirped mirrors are optical devices designed to manipulate the spectral properties of ultrashort laser pulses. They consist of multiple layers of dielectric coatings deposited on a substrate, where...

Chromatic aberration is an optical phenomenon that occurs when different wavelengths (colors) of light are refracted by a lens or optical system, leading to a failure to focus all colors to the same...

The ability of the instrument to separate wavelengths that are close together, numerically equal to the ratio of the shorter wavelength to the difference between two wavelengths that can just be...

A technique of using dyes during endoscopy to improve tissue differentiation. Dyes such as methylene blue, Toluidine blue and Lugol's solution all have the ability to stain particular types of cells....

The photographic filming of the action of x-ray images recorded on a fluorescent screen by means of large lens apertures and highly sensitive filters.

Circular dichroism (CD) is a spectroscopic technique used to study the structural characteristics of chiral (asymmetric) molecules, particularly biomolecules like proteins, nucleic acids, and certain...

A light beam whose electric vectors can be broken into two perpendicular elements that have equal amplitudes and that differ in phase by l/4 wavelength.

In optics, degreasers or ultrasonic arrangements used for removing pitch, cement or polishing material from lenses during manufacture. It also may refer to manual cleaning devices used immediately...

The limited light-gathering area of an optical system. The area is normally restricted to an edge or outer surface of an individual component. Also known as free aperture or objective aperture. The...

Denoting a finished circular edge. A decentered lens is adjusted on a centering chuck so that its image runs true, and the lens is then edged. A circular edge is one that has been cleared out....

That length over which energy in two separate waves remains constant. With respect to a laser, the greatest distance between two arms of an interferometric system for which sufficient interferometric...

A technique whereby two laser beams, one at an excitation wavelength and the second at a wavelength that produces Stokes Raman scattering, interact coherently in a sample, producing a strong...

A fiber optic communications system that works on the principles of homodyning or heterodyning. The transmitting laser produces an optical wave that is modulated in amplitude, phase or frequency by...

A coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers arranged in a specific geometric pattern to maintain the spatial coherence of...