Photonics Dictionary

A technique in photometry that uses an oxyhydrogen or oxyacetylene flame to optically excite a solution containing the sample to be analyzed.

One of the two major types of optical glass, the other being crown glass. Flint glass is softer than crown glass, has a higher dispersion and usually a higher refractive index.

An optical switch that controls conduction paths into and out of a junction in fiber optic and integrated optical circuits.

A material that surrounds a fiber optic cable's buffer tubes to prevent moisture from entering if the jacket is breached.

Flow cytometry is a powerful technique used in biology and medicine for the quantitative analysis of the physical and chemical characteristics of cells and particles suspended in a fluid. The method...

Fluence is a term used in various scientific and technical disciplines to describe the amount of something per unit area. The specific meaning of fluence can vary depending on the context in which it...

Optical glass that possesses a refractive index equal to or less than 1.5, and an Abbe number that ranges from 62 to about 85.

A device, also called a fluorescence lifetime instrument, that measures decay curves of fluorescing samples. It generally consists of a gated pulsed flashlamp or a cavity dumped dye laser...

Fluorescence microscopy is a specialized optical imaging technique used in biology, chemistry, and materials science to visualize and study specimens that exhibit fluorescence. Fluorescence is the...

A type of optical microscope that allows the specimen being viewed to be irradiated by ultraviolet, violet and occasionally blue radiation, causing the specimen to fluoresce.

Fluoride fibers are optical fibers made from fluoride-based materials, typically fluoride glasses or crystalline fluoride compounds. These fibers are characterized by their unique optical properties,...

Optical glass containing zirconium fluoride that results in special characteristics such as improved transmission.

The optical form of the crystal fluorspar, calcium fluoride, that is utilized for its low optical dispersion, its low refractive index, and its transparency to infrared and ultraviolet radiation.

A fiber optic device that uses a HeNe laser, beamsplitter, monochromator and photomultiplier to detect trace levels of chemicals and viruses in samples inside or outside the body.

A device used to scan, with a small, intensely bright spot, portions of a picture surface and to transform the original picture into a series of electrical signals. In optical character recognition,...

The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...

That point on the optical axis of a lens, to which an incident bundle of parallel light rays will converge.

In a symmetrical optical system this is a measure of the influence of the system upon the focus of a pencil of rays passing through it.

A device used to measure the focal length of an optical system or lens.

1. A mechanism that permits the focusing of an optical system.2. A means of obtaining the sharpest image from a cathode-ray tube display by adjusting the size of the spot where it reaches the screen.

A scale on an optical instrument that indicates the condition of focus. May indicate the distance to the object or diopter output, or from infinity focus.

1. A term used to describe the clouded appearance of an incompletely polished surface that scatters light. 2. The accumulation of moisture on an optical surface. 3. The extra spectral blackening of a...

1. A flaw in a blank caused by folding the blank's surface during its formation. 2. The change in the direction of a system's optical axis caused by a reflective component.

1. The sector of the Earth's surface registered upon a remote sensing device in a satellite. 2. The amount of space occupied by a component on the surface upon which it is mounted. 3. The space on an...

Observed lengthening in wavelengths of the optical absorption edge of a semiconductor with the application of an electric field.

The process whereby a rotating wheel carries grains of an abrasive, suspended in a vehicle, across the surface of the optical glass to be ground. The workpieces are forced downward by pneumatic...

A type of internal photonic connection in an integrated circuit in which a holographic grating is used to focus light at points on a silicon chip, maximizing the speed of signal propagation.

Freeform mirrors refer to reflective optical components that deviate from traditional symmetric or rotationally symmetric shapes, such as spheres or paraboloids. Unlike conventional mirrors, which...

A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with great accuracy. The term "frequency comb" is often associated with the Nobel...

A nonlinear optical process in which the frequency of an optical beam is doubled coherently.

A unit of frequency equivalent to 1012 cps. Named for Augustin Jean Fresnel, a French physicist known for his work in light and optics.

A Fresnel lens is a type of optical lens that consists of a series of concentric grooves or steps carved into a flat, thin piece of transparent material, typically plastic or glass. This design...

Fresnel reflection refers to the reflection of light at the interface between two different media with different refractive indices. This phenomenon was named after the French engineer and physicist...

Reflection losses incurred at input and output of optical elements because of the difference in refractive index between glass and the immersion medium.