Photonics Dictionary: C

A defect in an optical system that prevents rays from reaching their intended destination; it can be caused by an undersized aperture, a baffle out of position, etc. In imaging applications, removing...

This type of miniaturized system, referred to as CMOS qPCR, combines microfluidic technology with an ultralow-light CMOS bio-optical sensor with LEDs as the optical excitation source to achieve...

An imaging process in which the single opening of a simple pinhole camera is replaced with many openings called, collectively, the aperture. The recorded picture, which consists of many overlapping...

A reticle carrying patterns of various forms that can be rotated in an optical beam to cause variations in the intensity of the beam. It also is used in infrared detectors to scan the object field...

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...

The use of phase conjugation or other methods to increase the power density of a laser beam under adverse atmospheric conditions.

An optical instrument used to determine the distance to a target being viewed. Two similar optical systems view the target via 45° mirrors at the ends of a fixed baseline. One system creates the...

Cold atoms refer to atoms that have been cooled to extremely low temperatures, typically in the microkelvin (µK) to nanokelvin (nK) range, close to absolute zero (0 Kelvin or -273.15°C). At...

A method of applying antireflection coatings to optics that avoids the elevated temperatures normally used. A cold coating will not be as durable as a normal coating.

A convex or positive lens that serves to collect energy and direct it into subsequent system optics.

A positive lens located at or close to an intermediate image plane. The collector refracts off-axis light bundles, directing them into the apertures of subsequent optics.

1. The process of aligning the optical axes of optical systems to the reference mechanical axes or surfaces of an instrument. 2. The adjustment of two or more optical axes with respect to each other....

An optical instrument consisting of a well- corrected objective lens or mirror with a light source and or object/image (i.e. illuminated slit or retical) at its focal plane. Collimators are used to...

Certain color centers in the alkali halides have been optically pumped to produce efficient tunable pulsed and continuous-wave (CW) lasers emitting in the range of 0.8 to 3.3 µm.

A color center, in the context of materials science and condensed matter physics, refers to a specific type of crystallographic defect in a crystalline structure that introduces color to the...

A semitransparent mirror in an optical system that combines two or more output beams into a single coaxial beam.

The maximum rate at which temporally disjunct optical signals can be produced or detected.

An optical element that measures the phase difference between two components of elliptically polarized light to correct for mechanical or optical displacement.

1. A constituent part. It may consist of two or more parts cemented together, or with near and approximately matching surfaces. 2. The projection of a vector on a certain coordinate axis or along a...

A lens composed of two or more separate elements of optical glass that may or may not be cemented together. The surfaces of the elements are shaped to reduce or eliminate the aberrations inherent in...

A center-opening shutter made up of several identical leaves that are mounted symmetrically around the optical axis of the lens.

A method of producing large volumes of plastic optical components in which powdered or sheet plastic is pressed between heated dies.

Computer vision enables computers to interpret and make decisions based on visual data, such as images and videos. It involves the development of algorithms, techniques, and systems that enable...

The use of computer analysis in the calculation of diffraction patterns for information on the design of optical systems. In this method, the electric field amplitude and phase in the aperture are...

A computer-generated hologram (CGH) is a holographic image produced using computational methods and algorithms, rather than traditional optical techniques. CGHs are generated entirely in digital form...

The process of linking optical fiber end to end.

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In the context of geometry or optics, a concave shape is one that curves or...

Concave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These mirrors are commonly used in optics for various applications, including...

A reflecting grating ruled on a concave spherical surface that not only disperses the light but focuses the spectrum. The great advantage of this grating lies in the fact that no separate collimating...

The distance between the center of the two concentric circles of an optical fiber that designate the diameter of the cladding and the center of the two concentric circles that designate the diameter...

A confocal resonator, also known as a confocal cavity or confocal laser resonator, is a type of optical resonator configuration used in laser systems. The term confocal in this context refers to the...

Energy loss encountered at connectors in optical fiber transmission systems. The major contributors are mutual core displacement and fiber axis tilt. It is observed in both permanent splices and...

An optical instrument, generally a polarizing microscope, that is used to determine the interference figures and optical axis of a sample crystal. Also called a hodoscope.

The principle that states that optical instrumentation cannot increase the radiance of a source; the radiance of an image cannot exceed that of the object.

That property of certain optical devices, e.g., a penta prism, that maintains the angular relationship between the entering and the emerging rays traversing the system regardless of the orientation...

Method of disk rotation used for optical disk drives, in which the spindle motor decreases the speed of the disk's rotation as the head moves from the inner tracks to the outer, so that the radial...