Photonics Dictionary

Dual-chirped optical parametric amplification (DC-OPA) is an advanced technique in ultrafast laser technology used to amplify femtosecond laser pulses to extremely high energies while maintaining...

In data communications, the simultaneous operation of a circuit in both directions is known as full duplex; if only one transmitter can send at a time, the system is called half duplex.

An instrument that uses a photoelectric system to determine the size and volume of dust particles in a given unit of air.

A microscope that has been modified to permit the quantitative analysis of dust samples.

In atmospheric optics, the almost total blocking of light transmission in the atmosphere due to the scattering and absorption of the light by dust particles.

The superimposition of a pilot object on each hologram. The fixed relative position of the scanning and pilot beam during the recording process ensures that sensing and fixing the pilot beam position...

Stress applied to an optical fiber at a constant rate.

An optical correlator incorporating a binary phase-only spatial light modulator made from an iron garnet magneto-optic solid crystal and used in target recognition systems.

A spectroscopic technique used to display the intensity of an optical pulse as functions of time and frequency simultaneously.

A type of mosaic detector array that combines features of scanning and staring sensors by using a small rapid scanning motion (see saccadic motion) over a few pixels at a time.

The theoretical explanation and analysis of the interactions between electron waves and crystals used in studying electron diffraction.

In electrical equipment, power variations that are temporary (as opposed to the permanent, cumulative effects of drift).

The auxiliary electrode in a photomultiplier that gives rise to secondary emission and amplification when bombarded by photoelectrons.

The flat or angled surface, usually fine-ground, that limits the aperture of a lens or prism surface.

An edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the semiconductor chip rather than from the surface. Edge-emitting LEDs are...

In photoelectric sensing, the portion of the transmitted beam that actually functions in the system; the diameter of the beam that determines the presence or absence of an object by being blocked or...

The color of an object when it is illuminated by a nonisophotic source.

A scale attached to a microscope eyepiece that is seen superimposed on the image and that is used to measure the dimensions of the viewed object.

A unit of energy equal to the amount of energy absorbed by one molecule of material undergoing a photochemical reaction, as determined by the Stark-Einstein law.

Three proportional coefficients labeled Am, Bmn, and Bnm, that respectively characterize the rate of spontaneous emission, induced emission, and absorption of radiation by an atom, ion or molecule.

The organic inclusion in quartz crystal that forms delicate films and microspheres and that shows a maximum absorption at 450 nm.

Any lamp whose emission of radiant energy is dependent upon the passage of an electrical current through the emissive medium.

A device that uses four electrodes set in an alternating positive-negative polarity series to focus the beams of charged particles employed in electron microscopes and particle accelerators.

A lamp that uses the transmission of an electric current through a gas or vapor to produce illumination. Neon, mercury and argon lamps are examples of electric-discharge lamps.

Expression of the length of a transmission medium in terms of wavelengths of the propagating wavelength. In general, electrical length is an expression of physical length in wavelengths, radians or...

A device that detects radiation by utilizing the influence of light in forming an electrical signal. It may be a phototube; a photoconductive, photovoltaic or photojunction cell; a phototransistor;...

An electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an external electrical signal. Electro-optic modulation is a fundamental...

A radar system that uses electro-optic rather than microwave instrumentation and methods to perform its acquisition and tracking functions.

A type of optical modulator with potential application in optical switching and displays, in which applied voltage causes a change of interfacial tension between mercury and an electrolyte, varying...

Type of solid-state display tube in which the readout surface is coated with a material that changes color when positively or negatively charged.

A device consisting of an airtight quartz tube that holds the material to be analyzed. When a high-frequency electrostatic field, generated by microwaves, is applied to the tube, it emits energy of a...

The study of the generation of electromagnetic power by radiation from high-energy beams.

An electrochemical process of metal fabrication using an electrolyte, an anode to supply the metal, and a control of the electrical current and of the deposit of metal on the matrix of a reflector.